That would be the question.
We don't fight Putin, btw, but the Russian state, and target Putin as the de facto dictator of the state.
We're not ever likely to go to war, even with proxies, against Israel, not only due to the powerful Jewish poliical influence in the U.S, but obviously due to disproportionate influence in media and academia, much like the Episcopal Church had for centuries here, but on steroids.
Add to that the superstitious regard of Evangelicals for the State of Israel and you have the reason a string of presidents have tolerated the intolerable.
But, even with those aside, it comes down to the nature of Israel's problems being somewhat internal, like a civil war, and the unlikely case for America ever invading a nuclear power, another nastly little exception granted Israel. We go batshit crazy all the time with warnings of North Korea or Iran being on the verge of nuclear arms, yet we remain silent to Israel's holding them. Plus, every action with Israel and the Arabs is a lose/lose, as you're siding with bad actors on either side.
Now, we've seen clear evidence that Israel has no qualms with prosecuting its own genocide of its neighbors without the bother of ideology and whatnot: just blow them to smithereens while claiming every child is a shield for your enemy. Marvelously effective that.
Since there is zero chance Israel will ever surrender its own nukes, it becomes inevitable that Iran or one of the Arab states will eventually arm. And with Israel's demonstrated bloodthist this year, a great deal of those looking on are less sure she would use them in a last-ditch fight.
Gee, don'tcha miss WWI?