Why wouldn’t US insert military forces under auspices of protecting their humanitarian aid personnel? Distant forces don’t make any sense. Russia is much less likely to engage if there is powerful presence.

Because the military rarely deploys a force it can’t supply, reinforce or withdraw. Bataan will never fall again. Logistics is the obsession of the US Armed Forces. But small numbers of men with sigint, EW gear and things of that nature may come in. I’m not saying it will but it would be possible. In general, whatever you don’t want Turkey to know about will be on a US asset. The heavier stuff — antitank missiles, smart mortar shells, etc, my guess is that will go via Turkey or is on a Navy ship.