I think we can all agree that no country thinks that America is actually "weak". Reluctant to finish what we start, maybe, but never weak. A weak country would be easy prey-but then again, a weak country wouldn't be worth the trouble. A superpower might nuke a weak country every ten years, but it's just as likely that the weak countries aren't worth the cost of a nuke to bother, unless the country is conveniently or strategically located. (When's the last time anyone went after Andorra, or Luxembourg, for their own sakes?)
I resist the idea that truly think that America is weak. We've been more or less safe from attacks on our own soil for the last 4 years-could a weak country protect armor itself that quickly, to that much effect? Or is America strong enough that aggression towards us just isn't worth us-unless we show up in someone else's territory?
Weak is one of those words, like evil, that is easy to throw around about an enemy. It's hard to rouse the troops against a strong, stalwart and good foe. Then again, it's really more of a convenient insult than anything else-it's hard to honorably declare battle against a weak foe, if you honestly believe the difference of power is huge. (As an analogy- a sumo wrestler may very well call a slightly skinnier sumo wrestler weak, and wrestle him-but an honorable sumo wrestler isn't going to pick a fight with a skinny accountant.)
Our enemies may very well think we give up to early, or that we don't clean up after ourselves, or that we just like to meddle-but no one thinks we're "weak".