If Biden sticks by Trump's U.S.-Taliban withdrawal deal, then he owns very little of the results, some of which won't be immaculate. Post-withdrawal, can talk about "concern" for any events as they unfold, reiterate commitment to hit terrorist groups with intent/capability... 1/
to harm U.S. and its interests, but generally practice benign distancing from internal politics of AFG. Can also say that he was fulfilling Trump's deal and the die was cast, even criticize it (and people like me) as needed for political reasons - but stick to plan knowing... 2/
...that he doesn't want to have to own an endless war he should know will remain a headache for US and a suck on resources better used elsewhere. 3/
4/ But if he reneges on the deal, the conflict becomes Biden's War. Whether based on some "conditions" or a "spirit" of the deal that isn't in the text for all to see, he'd have to make an active choice to return to what we've been doing - and not doing well at - for years.
5/ Then Biden owns the results. This will include continued violence, but this time with US/coalition forces in crosshairs. Deciding to remain won't wave magic wand & make things better than they were before the deal; conditions on ground still only "modicum of success" at best.