Check that…he could have added more troops, set up an armed enclave, told the taliban that Trump didn’t really sign that surrender and hope for the best.

Honestly not sure – were you being sarcastic here? Why couldn’t he have done something like this?

There’s also the ever-possible “find some technical violation the other side did and back out,” or “find some issue that’s larger than imagined and unilaterally delay the agreement,” etc. Who was going to hold him accountable?