Well, I figure Bane and Talia needed each other in order to enact a plan on the scale that they did. She needed him as a leader and enforcer, and he needed her resources. I think after two failed attempts to bring down Gotham, it was go big or go home. They needed a game-changer. That fusion reactor was crucial to the entire plan, and that was really Miranda's baby. Bane was a great tactical leader, but a viable mole in Wayne Enterprises is a hard thing to come by- and that's leaving Bane's personal adoration of Talia off the table.
The nuclear threat made for a very unique scenario in which Bane could rule over Gotham without interference from the government or outside world. Even if Bane did have his own independent ambitions for supervillainy, I think it'd be hard for a guy like him to turn down the prospect of such power and grandiosity. I get the feeling he sees any position of power as a natural entitlement. I mean, even though the plan ultimately failed, his name gets a special place in US history books for his unprecedented acts of war.
And you're right, you could make that argument that the actual LoS aren't really in the film and it's all just his mercenaries and other men he recruited in the sewers- either way, they all fiercely respect and fear him, and I think that's always a position he'll gravitate towards. Even he hates Ra's (which I'm not entirely sure about), it doesn't mean he hates the ideals behind the LoS or that he might not still fancy himself the right man for the job.
Originally Posted by TheBat812
To sum it up: The LOS is a terrorist organization that disagrees with the values of Gotham's society. "When a society reaches the pinnacle of its decadence" they come back to reset the balance. The Gotham presented in TDKR is rife with examples of this (which are discussed in detail throughout the thread). It was never about street crime, it was about the balance of society and the values they adhere to. They attack Gotham because it is the biggest city that represents Western civilization, so by attacking it and changing their perception, it would have a domino effect throughout the Western world.
Very true, and that's why allowing it to crumble of its own people's volition was a huge part of the plan and took it to a territory that was a lot more unsettling than Ra's trying to accomplish the same thing via a chemical attack. It was more like the Joker's ferry experiment on a city-wide scale that resulted in a complete breakdown of society. It showed how weak and vulnerable the rich and powerful really were when the chips were down.