If I watch the two react to the bombing.
The essential problem, for better or worse the USA has a humongous military. If you ask the US diplomats, "Are you going to use the military for first use of WMDs", they say no. Then they are stuck, by definition, the only other first use for the military is to prevent first use by others.
I do not have to reveal my preferences to point this out, is is a tautological result. If it is a problem, then reduce the military size. Then what? Would we promise no first use against an existential threat?
Putin should figure out that we are stuck, and we know that he knows that we all know this is a stuck position.