"I say the warhead does not go off, or the guidance systems take it into the great lakes."
I'd bet that it's blow-up in air on the way to the target.
Although these "sub-plot's" are annoying...these writers do a heck of a job!
They are going to drop Jack onto the speeding warhead from a B 1 bomber. He is going to lasso it and ride to France where he will crash it into the Eifel Tower. Moments before he will ignite his jet pack and ride out of harm's way.