I agree with you, but I see a secondary strategy emerging:
Usama and his minions seem to be trying to overthrow key muslim allies and install a pan-Islamic empire that is nuclear capable.
So they undermine Saudi Arabia, Egypt, Syria, Jordan, Afghanistan, Pakistan, and Iraq,etc hoping to overthrow the leaders and incorporate them into their empire,under one leader, with their armies and military capabilities, to use against the West.
Then they launch World War III ( or IV) when they consolidate their gains and establish control.
All they need is one good military leader, millions of followers, and some good fortune on the battlefield.
Interesting analysis! I think, however that were this to actually happen as soon as we could identify concretely any nation-state as falling into an AQ camp status, with nuke capabilities, we could do a pre-emptive strike to degrade the threats. Not having a base of ops within a country "openly friendly" to their cause has been their strength and what has hobbled us in the past. Thus it would never get to a WWIII or WWIV stage before we acted rather decisively to take them out. Of course, this presupposes that we are capable of acting as a world super power. IF we have been pulverized and shattered from within by multiple nuke strikes first...well then it's a whole new ball game, right?