Originally Posted by Spider-Fan
Al Qaeada still operate under an idealogy of religion and other factors that are tangible and can be researched and explained. They don't blow themselves up for no reason. The League of Shadows in this film want to do the suicide mission for...science?
There is a big difference, and the film's attempts at motivation are sketchy at best. This film wasn't doing anything deep by leaving their motivation largely unexplained. That is just poor scripting.
Wait. You're saying that the League of Shadows didn't have a motivation in this film/trilogy?
Yes. They weren't religious fanatics. But they do have solid motivation that is established in Batman Begins
They see themselves as the stewards of society. They serve as the check that balances it.
"The League of Shadows has been a check against human corruption for thousands of years." -Ra's al Ghul
The League of Shadows' motivation was to seek out and destroy corruption in its various forms. They view the contemporary and accepted justice/legal system to be fundamentally flawed and broken and feel that it is their job to fix it. And to them, fixing it means destroying and bringing down those systems entirely.
When Ra's died, Talia and Bane took up this belief. Talia seems to have modified it a bit. She seems to be more of an ecological terrorist than her father (which he is in the comics) and that she wants to destroy Gotham because of the affect Gotham has on the world.
Bane seems to be more in line with Ra's al Ghul's beliefs than he is the environment like Talia is.
But I'd say their motivations we anything but non-existant or poorly executed.