I think CENTCOM made a strategic mistake from a strategic misunderstanding. They thought the base in Jordan was “safe” even while the mission of that base was in support of U.S. units in both Syria and Iraq - both of whom have come under increasing embrace with the Mullahs in Tehran and Russia. Sooner or later that base in Jordan was going to be target.
Notice too that Jordan is not offering to respond to an attack on its territory.
The kings of Jordan have always had to walk a fine line to hang onto the power bequeathed them by the British. If not “faithful” enough to “the Palestinians” their own population will remove them.
No need to have troops in Jordan or Syria. If we vacate Iraq, that would cause a vacuum that Iran would fill. I would want to reduce our presence at a minimum though. And maybe the Turkish and Saudis would fill that vacuum instead, if we played the right cards. That said, I don’t have any confidence that either Biden or Trump would fix this. As Trump has always said, our leaders are stupid.