Standard disclaimer: I do not own Mass Effect, nor any other content that you recognise. Some characters and systems are original creations. I am receiving no money for my work.
London – Earth
2017.10.28
I made a tumblr for this story. The fourth council race dot tumblr dot com. On there you will find things that I am going to try and describe without taking up too many words in the story. It currently has two maps that I have made of the area of space surrounding Earth, along with a more detailed look at the shirt sleeve garden world colony/city design. I bastardised Atlantis from Stargate Atlantis for the ground footprint of the city. As more chapters get posted I will post other things as well.
I am going to resist posting my large number of spreadsheets that tell me everything from planet population through time, to a specific ship's length and firepower. That way you guys won't notice when I have to change something because it didn't make sense as the story progressed! Numbers are the key to realism, currently every chapter has needed a new spreadsheet so that I have realistic numbers. This one was figuring out the impact of a 4 kg kinetic rod from various launchers along with its death/crippling injury/destruction/severe damage blast radius from each impact strength to allow the turians the orbital strikes from cannon without also breaching the cannon Citadel ban on bombarding garden worlds -.-
Right on we go, I hope you guys like the next few chapters. Army scale ground battles are the things I find most difficult to write currently so I hope the way I have done it is ok.
Qinghai – Shanxi
The journal of Lt. General Jack Williams
2112.10.01
It is sunrise above ground and as much as I wish I could see it, instead I thank God that the defences are complete. The Alliance's policy is that a city's maginot line must be completed before it is allowed to grow beyond 1 million people, I only wish I had the soldiers to man all the defences. They were designed to be held by an army corps and I have only a single division under my command, dam the general staff for requiring 4 million inhabitants before increasing the garrison to a corps.
I am 332,000 men short of what I need to man the line properly, if it were not for my faith that God would not give me an unachievable task, I would think our defeat was simply a matter of time. I have taken as many steps as I can to maximise my manpower, the catering, logistics, and non-weapon maintenance duties throughout Qinghai's maginot line are now being performed by civilian volunteers. Even if they are logistics officers that haven't held a weapon since basic training, I still need all of my soldiers on the front line.
The police are guarding the shelter entrances, the armed response squad officers are giving the normal police officers a crash course in firearms while we wait for the enemy attack. I hate to press them into potential combat duty when the vast majority have no weapons training, but I have no choice. I have no men to spare for rear-guard duties, the thin line of Alliance blue is that is all that stands between these invaders and the 882,920 colonists who came to this city to make Shanxi their home. Trusting the Systems Alliance, trusting us, to protect them. The navy has failed, the army must not let them down.
My two infantry brigades are garrisoning the line, I have rearranged them into two shifts of twelve hours each. It will be tough on the soldiers, but I need to cover for the four missing infantry brigades. The lines fort and bunker guns thankfully have slave circuits for situations like these, one gun in a section can be ordered to simply copy the target selection of its manned neighbour. It is far from ideal, but with the garrison at only 1/3rd strength it will most likely be the difference between victory and defeat in the fight ahead.
The 6,000 marines I have recalled from all the ships in this cluster will be integral to the defence plan, there are far fewer of them than the 55,000 soldier army infantry brigade I would prefer, but they have always boasted that their training made them worth 10 soldiers. We will see in the coming days if those boasts are empty rhetoric. They arrived just after the evacuation of the villages and towns were completed, there should be no one left outside the city limits now. Everyone should be safe in the shelter network as long as my forces can defend the city.
The aliens orbital fire has destroyed the entire centre of the colony and all of its traditional buildings, and still it continues. Were we and the civilians above ground, it would be devastating to morale and combat readiness. As it is, safe below ground in the maginot line and the shelters, all of this destruction is simply fuelling the fire of defiance both in my soldiers and in the civilians.
Personally, as much as it pains me to see Qinghai's forbidden city and her pagodas destroyed, the destruction of the cathedral, the mosque, the synagogue, and the temples has been worse. Ancestral, Buddhist, Hindu, Taoist, Confucian, Muslim, Christian and Jewish alike, their destruction has been much more devastating for a man of God like myself. It has been a constant battle the last two days to follow the Pope's directive not to hate the alien, to remember that they are children of God as well. I hope that I will still be able to follow it at the end of this invasion.
They have not targeted the main spaceport, so I still have the faint hope that they will land there and the explosives my engineers have placed will be able to destroy their first wave along the with port. It is a very faint hope, their bombardment has been thorough and professional despite their view of civilians as legitimate targets. As much as I wish them to do so, I do not think that they will fall for that old trick.
I had hoped to write about the preparations of my own armoured brigade, we must somehow take the fight to the enemy without the two other armoured brigades that are supposed to be with us. I have had some ideas, but the sensors have just shown the first enemy troopships entering the atmosphere.
It seems the wolf is at the door.
Pater noster, qui es in caelis, sanctificetur nomen tuum. Adveniat regnum tuum. Fiat voluntas tua, sicut in caelo, et in terra. Panem nostrum quotidianum da nobis hodie, et dimitte nobis debita nostra, sicut et nos dimittimus debitoribus nostris. Et ne nos inducas in tentationem, sed libera nos a malo.
Amen.
Qinghai Outskirts – Shanxi
2112.10.04
General Vetra Sparatus was really beginning to hate this planet and its inhabitants. The memories of the last four days flooded back as she stared at the map in front of her, fighting off the feeling of apprehension as she reviewed her plan of attack.
Everything had been going so well at the start, Admiral Arterius had dispatched ships to the four station colonies to capture them. As expected, they had encountered resistance in their docking bays from the alien's garrison forces, so the navy had withdrawn and destroyed the life support systems of the space stations and technology dependant colonies. It seemed the prospect of suffocating and/or freezing to death focused the minds of this new species as well as it did the currently known ones, and the four station colonies had soon surrendered. The civilian population had then been allowed to repair their life support systems once the garrison troops had laid down their weapons and marched into captivity.
Her good luck had seemed to be turning into a winning streak when the navy entered orbit of the class 1 and 2 garden world colonies as neither world had any surface to space anti-orbital guns. Granted those sorts of guns were generally a waste of resources, they were almost always overwhelmed before they did significant damage to an attacking fleet, but several races used them to buy time.
The main thing they did was force the attacking ground forces to strike immediately and in predictable locations, not having her invasion strategy dictated by the need to capture or destroy the guns before a full landing could occur was a pleasant surprise. Enjoying the relative ease of the operation to that point, she had approved Sub General Orinia's request to begin landing her troops in close proximity to the alien's dome colony. That was when things had started to go wrong.
Sub General Orinia had landed with her 100,000-strong sub legion on the moon of the gas giant and had quickly punched through the defences around two of the entrances. Fighting through the docking and supply areas, her forces had quickly broken through into the dome itself, but once inside they had found no resistance, just a city that appeared abandoned. Orinia's forces had advanced cautiously, but they had only gone a dozen metres before the first snipers and artillery opened up, killing and wounding hundreds in the opening minutes as the inhabitants destroyed their own city to hit the invading forces.
It had been nothing but grinding urban warfare ever since, the nightmare of every turian general when on the attack. With the dome preventing accurate orbital strikes, even if General Orinia was prepared to endure the logistical nightmare that would be caused by her entire army fighting in sealed armour due to the unbreathable atmosphere flooding the dome through the punctures, her forces were forced to fight room by room.
The General's situation wasn't helped by enemy forces constantly using the sewer network and service tunnels to pop up in previously cleared areas and strike from the rear. Every heap of rubble, whether in front of their own lines or behind them, was a potential death trap for Orinia and her forces. As if that was not enough, the troops had encountered two hardpoint fortifications designed to look just like an ordinary building, but actually capable of surviving intense artillery bombardment. The casualties inflicted by the defenders had been severe.
Spirits only knew how many more of them awaited Sub General Orinia's advancing forces, but they wouldn't find out any time soon. The advance had been painfully slow, in four days Orinia's forces had made it only a few hundred metres into the dome colony, and the enemy resistance showed no signs of faltering.
General Sparatus's own battle on this class 1 garden world was not fairing any better.
In the beginning it had seemed to be a standard, even easy attack. From orbit it was clear that only one area of the planet was currently inhabited, a city with small villages and what seemed to be a couple of partially built towns scattered around it in a circular area, approximately 600 km in diameter with the city at its centre.
They were all abandoned, the population presumably having been evacuated to the city. The main space port, some 100 km away from the city, was abandoned as well, but she wasn't falling for that old trick. She had bombarded the railway connection between the spaceport and the city and had left it for possible capture later.
The city itself was small, obviously just at the start of its life. There was a clear central area filled with open green space and what were probably historical building recreations based on their size and construction materials. Surrounding it, beginning to fill in the visible footprint of a six pointed star, were six 1 km tall archologies, linked together with elevated walkways and plazas.
The plaza's and walkways were partially made of transparisteel and transparent crystal, to allow light to filter through in rainbows to the ground below instead of blocking it out, showing this species valued art and appearance as much as functionality in its cities. Two parks and two lakes seemed to be under construction in four of the voids between the spokes of the star.
The remaining two voids seemed to be taken up by two small space ports, but the archologies had what appeared to be heavy anti-air emplacements on their roofs making a lightning assault on them impossible even if she was prepared to risk a similar booby trap as that which was no doubt awaiting her at the main spaceport. At the end of the footprint for each spoke was a 10 story high fort, with a heavy artillery emplacement and four heavy anti-air emplacements each.
Adding these emplacements firepower to the ones on the top of the archologies, the city was a death trap for any form of aircraft that the defenders didn't like. Together, they provided total anti-air coverage of the city and the surrounding area, and several could be destroyed or disabled before gaps started to appear in that total coverage. Encircling the city was a line of small hills, approximately 1 km in width and 250 km long in total. Some were natural, and others were obviously artificial, but the most interesting thing was that the valleys and routes through the line all appeared to be guarded by forts. The analysts had only spotted them due to their gun emplacements and firing bells being above ground as the majority of each fort was buried deep in the hills.
General Sparatus remembered laughing at the realisation that the primitives thought that a set of small hills could stop an invader, even if they did encircle the entire city and had forts built into them. That laughter hadn't lasted past the first day. Following her targeting criteria, the navy had begun the orbital strikes as she brought her troopships down well outside the enemy's anti-air net.
Turian warships were equipped with multiple launching systems on their ventral surfaces that launched 4 kg kinetic rods, impacting with a force of 0.4 tons of TNT from frigates, and 1.7 tons and 3.9 tons from cruisers and dreadnoughts respectively. Admiral Arterius's cruisers had rained down their kinetic strikes all day, and with a blast radius of 52m from their kinetic rods, 104m diameter craters had begun appearing all over the primitive's colony.
The targeting criteria had prioritised the centre of the city and one of the archology's, a standard tactic to attempt to demoralise the civilian population and cause them to force their military to surrender without turian forces even having to commit to a ground attack. Just in case these civilians were more stubborn than the population of the station colonies, General Sparatus had also targeted all of the anti-air forts and the visible gun emplacements in the line of hills, to let the military know that they were beaten and she could just pound them into dust from orbit, encouraging them to listen to the civilian demands for surrender.
After a full day of bombardment to produce enough shock and disruption to the defenders, the centre of the city had been reduced to flames and rubble littered with craters, as expected. The high plazas and walkways linking the archologies together had disintegrated under the kinetic strikes, shattering and falling to the ground in a rain of metal shrapnel and crystal shards. But that was where it ended.
To the utter surprise of her, her officers, the navy officers, and the Admiral, the archology was untouched, defended with a kinetic barrier. This wasn't impossible, the archologies were only 1 km high, the length of a modern dreadnought, and the barriers were only civilian grade in terms of power, so it wasn't like the defenders had had to find a dreadnought drive core's worth of eezo to protect each one, but still. No one, not even the asari, used kinetic barriers to defend entire skyscrapers from orbital kinetic strikes, those races that had the defensive mindset either didn't use archologies, didn't have the eezo, or didn't have a strong enough economy to pay for it.
As the dust had continued to clear, the General had felt her apprehension grow. The anti-air forts were protected by cruiser grade kinetic barriers and had suffered no damage at, all while the visible gun emplacements in the fortified hill line had been constructed using what seemed to be frigate grade armour. The day of kinetic strikes had dented them, but that was about all that they had achieved. That armour was designed to take a glancing blow from a frigates main gun without failing, which meant that given that a turian frigates main gun hit with a firepower of 5.4 kilotons of TNT on a direct hit, no artillery she had, ground or orbital based, was going to do more than dent the alien's forts.
The civilian grade protecting the archologies prevented her orbital strikes from destroying them, but they should be vulnerable to focused, close range, ground artillery fire, as even this race of engineers couldn't afford to wrap their archologies entirely in armour. The anti-air forts on the city's internal perimeter were another matter entirely. The warship grade kinetic barriers protecting them were almost certainly supplemented by armour which would make them truly tough nuts to crack, and completely rule out any form of air attack on the city until she had dealt with them. narrowed her possible attack method options drastically. The only thing that would allow her to destroy the city anti air forts and perimeter hill defences from outside return fire range would be firing the main guns of the navy's warships at them, but that was in direct violation of one of the strongest Citadel Conventions, ie: Do not bombard garden class worlds whatever the reason!
If she broke that law, she would be vilified for all eternity by every inhabitant of citadel space, and so would everyone under her command.
General Sparatus had promptly banned anyone from referring to the aliens as primitives and had begun pouring over the scan and reconnaissance data with a great deal more caution, while the forward operating base continued to be constructed around her. After she and ordered it moved to x5 the estimated maximum enemy artillery range rather than the standard x3. She was taking no more chances with this operation.
While this was ongoing, she had dispatched a small force under Captain Desolas Arterius to capture the alien's main spaceport. As expected it had promptly exploded on his arrival once he had proved that he was not going to obligingly walk into the middle of it, but Captain Arterius had conducted a thorough search of the surviving warehouses, rail terminal, surrounding area. He had come back two days later with some form of artefact that he had found in one of the less damaged warehouses and some prisoners. Apparently, the artifact was completely different to the local alien's technology, it was ancient in fact.
The Captain had speculated that the locals had most likely found it here on this garden world at some point since their arrival, or had found it elsewhere during their exploration of the surrounding systems in this cluster. Regardless as to how the aliens had found it, Captain Arterius was now on a frigate taking it back to the Hierarchy for study with strict orders to be very vague as to how it was found until this situation was dealt with and became public knowledge.
The prisoners were team of local mercenaries had apparently been guarding it. An appalling dereliction of duty on their part, to be sticking to a contract rather than helping their army at a time like this. That had been the main reason why she had been willing to believe Desolas's assertion that they were mercenaries, not soldiers, when no one could actually ask them because they still didn't speak the enemy's language.
Desolas had taken all three of the mercenaries to Palaven with the artefact, in case they had information that would be useful when the Hierarchy's scientists began their analysis. His father had extracted a very detailed and convincing promise for him to be careful with that artefact, before giving him a frigate to take it and the prisoners back to the Hierarchy for study.
They had been dispatched last night, just after the last of the landers had finished ferrying the Legions supplies down from the orbiting supply ships. Now, with the sunrise, the turian base had turned into a hive of activity as armour, artillery, vehicles, and troops martialled into their respective units.
General Sparatus took one last look at the map in her office before sealing her helmet and heading to her Command APC. The enemies defence line would be broken by sunset if they responded as every other race did to turian attacks. The doubt and apprehension continued to form a knot in her stomach, as it had done since the dust from her bombardment cleared at the end of the first day to reveal negligible damage to the alien city.
The turian in her had total confidence in victory, there was no other acceptable outcome for the Hierarchy Legions after all. The General in her was deeply concerned what the defenders had in store for her next, she had a feeling this was going to be one of the hardest fights of her career.
Washington DC - Earth
2112.10.04
Stacey Collins, American ambassador to the Systems Alliance, sat on one of the sofas in the oval office as President Andrew Goldwater and his Secretary of State, Laura Abrams, continued to look over the classified briefings from their last meeting. Finally, they turned to her and the Chairman of the Joint Chiefs, General Brooker.
"So, Stacey," President Goldwater began, putting the folder onto the coffee table, "the Chinese have blocked the dispatch of the Grand Fleet to Shanxi again?"
"Yes sir." She reported dutifully. "The Grand Fleet was assembled on time two days ago, and Fleet Admiral Carmichael requested permission to order them to sail out and engage the enemy yesterday. Ambassador Sheng blocked that request with his vote and the votes of China's usual allies, they did the same to the Admiral's second request today and aren't giving any indication that they'll stop any time soon."
"Laura, do we have any intelligence as to why?" The President asked his Secretary of State.
"We believe it's a purely domestic calculation Mr President." Laura Abrams replied, opening a different folder. "As we all know, China's recovery from their recent economic depression required some very unpopular measures, and the resentment that they generated among their population is still very fresh. We hadn't thought it was particularly worrisome for them, given the iron grip they usually have on their population, but it seems like the CIA may have dropped the ball on this one."
"Surely that would be all the more reason to dispatch a relief force to Shanxi quickly? Demonstrating swift, firm, and decisive action to their public?" Andrew asked, slightly confused.
"Not if they're not leading the relief force sir." Ambassador Collins spoke up. "How would you feel if North Carolina had fallen to a hostile amphibious invasion, and it was old United Nations peacekeeping soldiers that were sent to liberate it. All while the US Army sat in its bases, utterly useless, and the TV was filled with videos of United Nations soldiers liberating American territory and citizens without a single stars and stripes in sight?"
The immediate burning outrage Andrew Goldwater felt at the mere suggestion of such a scenario, even though the UN had been gone for 26 years, quickly brought him around to his ambassadors' way of thinking. "Point accepted. But the Treaty of Mars doesn't allow any of us to have a navy, at least officially, and I doubt whatever insurance policy warships China has constructed are enough to liberate Shanxi on their own, so what's their plan?"
"That's where the CIA thankfully hasn't dropped the ball sir." Laura Abrams jumped in. "Pretty much every shipyard under Chinese control is sticking life support systems in the cargo holds of every freighter they have. They won't be any more sophisticated than moving boxes that won't kill any people you put in them, but it will allow them to move Peoples Liberation Army soldiers to Shanxi in huge numbers. More than double the number of Alliance soldiers that Field Marshal Khatri is planning to deploy if our upper estimates are correct."
"So that's why they're delaying the naval response." President Goldwater caught on quickly. With the election to what would hopefully be his second term of office only a month away, politics was at the forefront of his mind. "They want any news of the multi-national Systems Alliance Navy's successes buried under pictures and videos of their heroic PLA soldiers liberating Shanxi from an alien menace, while the rest of us are on base guard duty or some other rear area activity."
"That would help their domestic political situation significantly sir." His Secretary of State confirmed.
"What's their timetable?"
"We believe that they'll be ready to go barely a week after Field Marshal Khatri, provided that she makes her publicly stated schedule."
"She'll make it." General Brooker remarked. "If anything, she'll beat it. Much as I don't like the Alliance military, Carmichael and Khatri are as skilled as they come, they'll succeed at anything they put their minds to.
"So," President Goldwater contemplated, "the question is what we want to do about it."
"Do we want to do anything?" Secretary Abrams asked. At the questioning looks of the others, she elaborated. "We certainly can peel off enough of China's allies to get a vote deploying the Alliance Navy passed, but it will cost us a huge amount of diplomatic capital, including several trade concessions that will really hurt our re-election campaign, and election day is only a month away. What if we just left the Chinese to it? Let them keep blocking the naval deployments until their ready to go?"
"It may only be a few weeks, but if the garrison's still fighting then those few weeks could be the difference between holding out until relief arrives or being utterly crushed." General Brooker pointed out.
"So what?" Secretary Abrams made a dismissive gesture. "It's not our colony. If the Chinese would rather it fall to aliens than have it be liberated by the Alliance? Well, that's their own business, the colonists aren't Americans."
"Some of the garrison is." A straight-shooting military person through and through, General Brooker had difficulty hiding their disgust at the Secretary of State's attitude
"Not much of it, and we'll be on record as having wanted to rescue them anyway. We're still voting to deploy the Alliance Navy after all, we're just not stopping China from blocking it."
"Diplomatically there's not too much risk." Ambassador Collins mused. "China's already our rival, and Mexico and Argentina need us too much to make more than token protests about Zapala."
"The military fall out?" President Goldwater mused, looking to his Chairman.
General Brooker still looked disgusted at the direction the meeting had taken, but they still gave the honest military advice that was asked for. "Either we can beat them, or we can't. There's not enough population, industry, or combat assets present in the Centauri Veil to effect that. If we can beat them, then militarily the only difference waiting makes is to drastically increase projected army casualties due to having to fight an enemy that has already pacified their target and dug in, instead of squeezing them between a defiant garrison and a fresh relief force. If we can't beat them then it doesn't matter if we go now or later."
"And if the aliens decide to kill everyone with nuclear weapons or kinetic bombardment while we're waiting?" Ambassador Collins asked the question no one else had been willing to.
"They have the shelter network to protect them from those sorts of attacks." General Brooker remarked hesitantly, suddenly grateful for the paranoia that the Prothean extinction message had generated.
"And China will be the one to carry the can anyway, we've been voting to send relief to Shanxi, it will be relatively easy to deflect the blame that we could have done more to make sure it passed, given that China has been actively making sure it fails." Secretary Abrams shrugged.
"Alright." President Goldwater decided "Stacy, keep voting to send the relief force to Shanxi, but don't expend any diplomatic capital on peeling away China's allies. If they want to gamble with their colony, that's their business. I see no reason why we should bail them out, especially if doing so would hand that jumped up governor the electoral college."
"As you wish Mr President." Ambassador Collins was better at hiding her disgust than General Brooker was. Accepting her orders, she said a silent prayer for the people of Shanxi and Zapala.
Codex Entry: Humans – Human Military Doctrine, Implementing the Endurance Strategy
(Citadel Codex, First Human SPECTRE Collector's Edition, 2183)
While keeping mobile warfare as its offensive and defensive naval doctrine, and its offensive ground doctrine, the key vulnerability of the mobile warfare doctrine to enemy air superiority caused it to be rejected as the defensive ground doctrine of the Alliance, despite mass outcry's that it was simply 'common sense' to defend a planet that way. The Alliance planners focused on the facts that if the enemy army has landed on a human planet, then the alien forces have at least orbital superiority, if not orbital supremacy, and that being subject to constant air attack has proved fatal to every mobile warfare based defensive war since was first invented.
The choice of the Alliance to approve the defence in depth doctrine based endurance strategy for defensive ground warfare was treated with contempt and derision by the nation states armies. Adding to the derision of the armchair generals in the media, the nation state armies laughed at the Alliance implementing defensive tactics that were seen as nearly 200 years out of date.
The vindication of defence in depth in the modern world of orbital bombardment, and the Alliance Army's successful method of implementing it in the First Contact War, was only enhanced by wargames released by Palaven Command in the years following the war. Revealing that attempting to use the 'modern' and 'common sense' mobile warfare doctrine to defend Shanxi would have resulted in a turian victory in only four days.
When creating the endurance strategy, Alliance planners decided to discount the idea of creating a defence for an enemy using nuclear warheads after the destruction of anti-air defences, or bombarding the planet's surface with the main guns of their warships. These were deemed impossible to defend against in an economically viable manner, and if faced with such an opponent the colony would either be forced to surrender to prevent a wholescale massacre of its civilian population, or hunker down in the civilian shelters and concentrate on surviving and awaiting rescue from off planet forces.
With their unique vulnerabilities and restrictions, it was decided to use the Stalingrad method of defence in depth to defend dome colonies. Sub surface shelters, disguised hardpoints, and concealed access tunnels were all included in a dome city's construction. This was because as the surface is uninhabitable outside the domes, all of the fighting would be restricted to within the dome itself, where armour and motorized infantry would be useless to a defending force. The dome itself was predicted to prevent enemy orbital strikes from hitting with any accuracy, if they were even willing to puncture it in the first place.
This left the Alliance with the challenge of finding a way to implement a method of defence in depth that was capable of allowing the defending forces of shirt sleeve worlds to survive the orbital kinetic strikes that would be the doom of any mobile warfare defenders. This had to be done while accounting for the facts that the colony had no dome to protect it, there was unlimited room for the enemy to manoeuvre around defending forces, and the early colonies themselves had tended to be very dispersed. The colonists had generally come to them to escape the cramped and overcrowded cites of Earth after all, and they were not keen to simply reproduce them on their new world.
Deciding to look to the last time a war was conducted under the threat of heavy artillery bombardment, the planners studied the First World War and the years immediately after it when military planners assumed that the next war would be fought under the same conditions. Finally, they came upon the idea that would form the linchpin of the Alliance's colonial defence strategy. The Maginot Line.
Much derided due to its ineffectiveness in protecting France from German attack, this failure was in fact due to the strategic planning failures and tactical manoeuvring failures of the French Command, rather than any deficiencies of the Maginot Line itself. Over 450 kilometres long, the Maginot Line was a line of major underground forts forming strong points, between which were smaller forts filling in the gaps between their fields of fire, further supplemented by multiple small one-man to five-man fortifications to engage any skirmishers who were too small in number to be targeted by the main guns of the forts.
Underground barracks and railways kept the troops safe and allowed them to man the forts without fear of artillery. There was no wall to stop an attacking force that fought its way passed the guns, that was not the intention of the line. Rather it was supposed to slow any attack to allow friendly forces time to rush to the area and counterattack. Immune to air and artillery attack it was the perfect ground-based defence against the mobile warfare doctrine, nullifying the shock and speed that were two of the three requirements critical to a blitzkrieg attack's success.
This is why the German attacks of 1940 CE bypassed the majority of the Maginot Line rather than trying to punch through it, and why the Italians proved completely incapable of breaching the Alpine 'Little Maginot' Line on France's southern border where there was no possible way around.
Considering that the 188 km M25 orbital motorway encircles Greater London, an area that had a population of 9 million in 2016 CE and 14.8 million in 2112, it was decided that all shirt sleeve Alliance colonies would have their major cities encircled by a 1 km thick by 250 km long Maginot line, 200 km shorter than the original.
With adequate underground military facilities, and major air defences put throughout the area to prevent the bypassing of the line by air, above ground green space for the cities inhabitants to enjoy, new colonies were convinced to construct their cities upwards instead of outwards, with the population housed in space generous arcologies approximately 1 km high with fantastic views. Greatly reducing the cities area footprint, this would allow the city to grow to a size of approximately 80 million people before a new city would need to be constructed.
Those who still wished for village or town living in traditional buildings in rural locations, rather than living in the archology cities, were allowed to found the settlements on the condition that a rail link to the city was installed. These rural settlements are bereft of military protection, and the inhabitants must use the rail links to evacuate to the cities as quickly as possible in the event of an attack.
As the city of Beijing managed to house 20 million people in a similar space with no building over 200 m tall in 2016 CE, this was deemed to be an acceptable balance between the defensive fortifications required, and the limitations that those fortifications placed on the city's ability to grow. It should be noted that on more developed garden worlds, an increasing percentage of the population chooses to live outside of the cities in small towns and villages.
In 2112, 90% of the non-Sol Alliance population lived in cities. By 2183 and the attack on Eden Prime, the increasing security of the garden worlds in the Alliance's core systems had dropped that figure to 70%.
The planners based their designs on orbital kinetic strikes of 1-44 tons of TNT as the largest bomb in existence at that time, the USA's MOAB, produced a 44 t explosion. For comparison, the main gun of a modern Alliance frigate produces a 2.4 kt explosion (2,400 tons of TNT). Alliance warships are equipped with kinetic rod launching systems on their ventral surfaces that allow them to fire 6 kg rods, creating explosions ranging from 0.3 t (frigate) to 14.2 t (dreadnought) in support of their invading ground troops, as such Alliance ground defences are designed to withstand impacts of this kind as a baseline.
These defence systems were put to the test for the first time when an entire turian army legion invaded the human worlds of Shanxi and Zapala in the first contact war.
Author's Note
Seeing how the turians fight exactly the same as we do today in cannon (except with a more callous attitude to civilians), and how easily our current method of combined arms mobile warfare falls apart when you lose air superiority (the Alliance fights that way in canon and gets pounded into oblivion by turian orbital fire), I came up with my own mix based on history and the demonstrated deficiencies of our current method of warfare when your enemy has a vastly more powerful air force (see most battles fought against the US army and air force since 1945).
For those who would like to learn about how the Maginot Line actually performed in WW2 rather than the reputation it has gained from wartime propaganda and post war satire, there are three good videos.
A quick general explanation
The Maginot Line: Actually a Good Idea
By: Historigraph (youtube)
A more detailed look at its construction and performance in the Nazi invasion
The Maginot Line – WW2 on Location – France 1940 – 01
Blitzkrieg in the West – The Invasion of France – WW2 – 038 – May 18 1940
Both by: World War Two (youtube)
Lastly, Ouvrage Hackenburg is the largest fort on the Maginot Line and is open to the public with tours in many different languages. If you find yourself near the French/German border you will not find a more fascinating place to visit! It's very reasonably priced as well.
Timeline Changes So Far
First colony on mars: 27 years earlier than canon
Discovery of Prothean ruins: 64 years earlier than canon
Founding of the Systems Alliance (council of nations version): 63 years earlier than canon
The First Contact War: 45 years earlier than canon