Galactic Politics - Economies of Scale and Interstellar Warfare
Even with the addition of the krogan and the rapid expansion of the League, the Citadel still out numbered and outproduced the League on every level. This had to do main with the vast difference in population. The quarians now numbered somewhere in the neighbor hood of 20 million, but over a third of their population was under the age of majority. Humanities population was somewhere in the neighborhood of 13 billion, with about 11 billion on Earth and the remaining 2 billion spread out of a dozen star systems and the various ships and space stations. The krogan population was somewhere in the neighborhood of 3 billion, and rapidly exploding. Like the quarians, the krogan population was set to undergo a major increase, and many projections estimated that within a generation, the number of krogan would double. However, that was at least 16 years (the time it took for a krogan to reach maturity) in the future.
This was to be compared with the population of the Citadel races. Just the planet of Illium was home to more than 20 billion sentients, 99% of whom were Citadel races. The minor races equaled the population of the entire League, and the major races were each equal in just their major colonies and homeworlds. This gave the Citadel an overwhelming numerical and economic advantage. While the League's economy was vastly more efficient than any Citadel economy, the entire League was still the fifth largest economy in the galaxy, behind the turian, asari, salarian, and volus economies.
This was noticed by many Citadel members, and quite a few of them called for a war of suppression against the League, before they could become a real threat. The problem was, those voices were mistaken: the League was already a real threat. With the development of their own Mass Relays, the League had enforced the ancient human doctrine of Mutually Assured Destruction upon the galaxy. Yes, they would a war against the Citadel. In the long run, they would be ground to powder under endless fleets they couldn't hope to match even if every member of their population was able to serve on active duty. What they did have was a gun pointed straight at the gut of the Citadel. It wouldn't kill the Citadel, but it would cause them to bleed for years, possibly dying of the wound, years after the League was nothing but a memory.
The problem was that the League could send it's fleets to bombard the Citadel races planets into a oblivion. No, they couldn't get every plant. They couldn't even hope to get a majority of them. But they could hit every homeworld, and render it uninhabitable with a kinetic bombardment. The Citadel was working hard on their own mass relays, and projections indicated that by 2168, the Citadel would finish it's own Mass Relay network. All this would do though was ensure that any war between League and Council would be brutal, short, and bloody. Though the League would lose the immediate conflict, whether or not the Council could truly win was up for debate.
Dozens of warlords in the terminus systems, long held at bay by the turians, were licking their chops in anticipation of a League/Citadel war. They could seize innumerable planets with the Citadel otherwise occupied. They would raid, loot and pillage, stabbing the Citadel in the back even as the League bled them white.
So then, the cold war continued, each side grasping for an advantage that would give it an edge. Each developed catastrophic super weapons, each built up massive fleets and each expanded their economies. Not since ancient days, before the Cycle of the Reapers, had the galaxy been so well armed and armored. Each homeworld had massive orbital defenses in place. Each mass relay was well guarded, with defenses that could cripple any fleet that attempted to come through them. Borders were heavily patroled, with warships of increasing power and size. Flotillas of cruisers and frigates eyed each other warily in contested systems. No blood had yet been drawn, but it was obvious to every one that it was only a matter of time before the cold war turned hot. Some dreamed of peace, but many more dreamed of war. Of victory. Of safety. Of a galaxy rid of their enemies.
And in dark spaces, the Reapers waited. A fleet of millions, with a single purpose. Harvest of all interstellar life. And in orbit of a tiny batarian colony, a wound festered. An infection that could bring destruction even to the mightest of empires.