Indifferent. We're not at war against the IDF. Go and join the French Foreign Legion for all I care, so long as they're not fighting American forces.
Replying to myself: indifferent in the context of Americans committing what I consider to be traitorous acts against Americans. If you go join the IDF and shoot your way through Gaza, I'm going to think you're a POS. But I think you'll be a different kind of POS than Fonda was in Vietnam, which is the discussion at hand here.
That's a bit of a weird position to take. You seem to put "American forces" in a special bucket where, even if the actions the US military are taking is wrong, the support and reputation of "American forces" should still be protected at all costs, and the people they're doing wrong things to don't get to have any support.
Let's imagine an alternate universe where Russia didn't invade Ukraine. There were rumors that they were considering it, though, and Europe was not feeling particularly secure, afraid that Russia would not stop with Ukraine. This Ukraine is, like in our universe, nominally an ally of the West, though not the closest of terms. Poland, a US ally and NATO member, afraid that Russia would invade Ukraine and use it as a forward base to attack Poland, decides to preemptively invade Ukraine in order to establish its own forward base, a buffer zone.
I think many people in the US, myself (half Polish from my mom's side) included, would think this was a horrible thing for Poland to do. A bunch of us decide we're going to support Ukraine, protest on their behalf, and donate to their cause. Would you object to that? If not, then that's hypocritical. If so, that's... not a great look for you either.