You guys are trying the "Super Presidents" argument in reverse again. Recall that Obama was a Super President whose exec orders should still be followed even after he left office. Now, the reversal of this is that Trump's decision was to be followed to the letter Because Reasons.

Not at all. This is not about whether Biden was required to make the same choice as Trump. It is simply arguing that there's no reason to believe that had he been re-elected, Trump would have made different choices than Trump did in his first term.

Trump decided that the U.S. mission of supporting the Afghan government would no longer continue. This was based in part, IMHO, on an erroneous assessment by U.S. intelligence and defense that the Afghan armed forces were capable of defending the government from the Taliban. Regardless, that was Trump's policy towards Afghanistan - and it's consistent with his desire in other theaters to draw down U.S. troop levels and reduce their overseas mission (recall that his Defense Secretary resigned over a decision to cut troop levels in Syria). Trump does not go in for formalized doctrine or precise formulations of foreign policy, but he generally felt that the U.S. was spending too much blood and treasure projecting military force in far-flung theaters. There's no reason whatsoever to believe that he wouldn't have continued the withdrawal from Afghanistan in a second term.

In a counterfactual world where Trump was re-elected, we would have still continued the withdrawal from Afghanistan. Whether orderly or chaotically, it still would have continued - because that was the decision that Trump had made in his first term, that was the agreement that Trump made with the Taliban, and that was the general direction of Trump's foreign policy. And once we withdrew, the Taliban would have taken over. Regardless of whether we left stuff behind and regardless of which airport we chose to staff. The decision to no longer defend the Afghan government was the relevant factor, not the specifics of how the withdrawal of American troops was conducted.

Biden owns the specifics of the withdrawal - but it's just flat wrong to suggest that the Ghani government would have been able to hold off the Taliban even if Trump had been re-elected. The U.S. project to build up the Afghani defense forces was a colossal failure, and the inevitable result of that failure was that the U.S.-backed government never had a chance once we decided to no longer prop it up.