Why they needed a large network of support:
I agree with most of your points (though I'm not sure why they would necessarily need fake IDs). My original statement wasn't worded clearly enough. As I said, they do need money, people, and a plan, and all of these travel easily. A network of supporters is very helpful and maybe even necessary, but a network is exactly that: a network. It's not a base or headquarters like, a couple of bunkers somewhere that you can drop a bomb on. It consists of supporters who may be dispersed all over the globe. They may be living in a students' dorm in Hamburg, with a criminal record white as snow, and not so much as a breadknife for a weapon. They may be living in a hut somewhere in the Afghan mountains toting old AK-47s. You can nuke away a couple of nodes of that network, but can you tear it all down that way? I doubt it.
You can (and should, IMO) set a precedent by removing top figures, you can try to pinch them wherever they are and make them keep moving. But I believe large scale operations with huge civilian losses will only serve to reinforce the network, at the additional cost of destabilising entire regions of the world even more than they are now.
The situation is much different yes, but is the enemy?
Yes, radically. Their mode of operation is completely different. The war against Japan or Germany had armies and front lines. Where are the armies and front lines in this conflict? If there is any similarity to conflicts of the past, it may be Vietnam or the USSR's Afghanistan trauma, only less localized. Or maybe the ongoing, neverending fight against the drug cartels, which have globalized their operations just as these terrorists seem to have. I see absolutely no analogy to WWII, unless you count the resolve that something has to happen.
It will not however be difficult to find the countries that support him, with his support removed he will be ineffective.
Others will follow. As I stated, there is a good supply of hate available, and I doubt that the money supply can easily be shut off (that's why I'm bringing in the drug cartel example).
f.