There is a precedent of sorts, Wake Island
The Marines and contractor forces on Wake were not relieved. By some accounts, help was dispatched and recalled. The story is that there was not adequate and timely help tp prevent the inevitable loss.
FDR was apparently not involved in the decision, it was the CINCPAC.
Wake is really not a valid precedent though. Although there were cables and other warnings of the deteriorating situation, there was not constant voice and video communication. There were no major installations just hours away. There were no lawyers controlling the military’s every action. There were no lawyers holding the CIA leash.
It will boil down to a decision based on what was percieved as legal rather than what was right . The American legal profession is very high up, near the top, of America’s enemies.
A prayer this situation does not go that way, but you could very well be correct, it perhaps will turn in that direction. Lawyers cause more trouble than the lawyers are worth. Normally boils down to legalities, regrettably, because our nation is a nation of law(s), and the rule of law, or the lack thereof.