A team is supposed to be strong. Unbreakable. There are three, you see, and so if one's hurt or tired, the other two are there to pick up the slack until the strength is back. If two are in pain, then the responsibility falls to the third member, who has the memory of the three of them and their strength to back him up. So, hypothetically, a team is never supposed to break.
It will always be there to support you.
It will always understand you.
It will always love you.
It will always forgive you.
No matter what. It doesn't matter if they fight, if harsh hits and harsher words are exchanged between them, if hurt and anger flares on both sides, because in the end they are together. A team. Nothing should be able to break that bond.
Not even when a member of the team deserts them.
Not even when they betray you.
Not even when they leave you unconscious behind them.
Not even when they try to kill you.
Not even when they punch a whole through your chest.
None of that matters to a real team, because a real team will always understand, and it will always forgive.
Tsunade and Jiraiya watch Naruto and Sakura, watch them train and try, determined to bring back their lost boy, their lost teammate. They still believe in him, still believe that if they get him back, everything will be all right because they will be together again, a team again, and everyone knows teams are strong and unbreakable. It hurts them, watching the children's idealism (because despite numerous protests they are children still) and remembering their own. Remembering their own determination to bring Orochimaru back, and how that dream and desire was crushed, along with their team, and knowing that someday, Naruto and Sakura will experience those very same feelings.
Because the truth is, teams aren't strong and unbreakable. They're weak and fragile, and all it takes is the abandonment of one to make the other two fall apart. They weren't able to be strong enough for him, and he wasn't able to change for them. So he left. Jiraiya left. Tsunade left. And their team was nothing but a bitter memory in the back of their minds.
Both Jiraiya and Tsunade know that one day, they will kill Orochimaru, either separately or together. They know this, just as they know that their team is broken, that it broke a long time ago and nothing and no one can put it back together, but sometimes, when they look at their students, they wonder what would've been if they hadn't given up, if they had managed to bring Orochimaru back and make him theirs again, make them a team again.
Because when they see that absolute resolve and determination on their apprentices faces, they can't help but believe, even if just for a moment, that they will get Sasuke back and everything will be all right.
But then they remember that life isn't perfect, and what a team is supposed to be is not what it is. They remember that they hate Orochimaru now, although a small, unspoken part of them still loves and understands him, even if they can never forgive him, and that someday they will kill him, just as, if Itachi doesn't finish the job first, Naruto and Sakura will kill Sasuke.
They remember that a team isn't unbreakable, no matter how much they might wish it.