Here  >>/54881/ I drew attention a breddy gud video serious about why the war on Ukraine can't be ended. To recap:
1. Five State War (not 2 but 5 participants)
2. Divided Executives (cliques and individual thoughts within all the participants)
3. War Termination Phase (everyone wants to reach peace on their own terms)
Generally it is not acknowledged openly that it's not just Russia and Ukraine participating tho Moscow says so sometimes but to be honest it should be apparent for an observer who invest a little time into studying the war.

In case of the Iran war, this situation is more apparent. Still not said openly by many, but it should be quite obvious. The war has three participants with their own mind. USA, Israel, Iran - where Israel is not a junior partner in this. It's not like how Hungary's participated in Afghanistan. The US has no control over Israel. They could put various pressures, but then they could have just avoided this conflict altogether.
And as Jeff Rich says in case of Ukraine, all participants have to make their own separate peace, in case of Iran they also have to. The US could get out of the conflict leaving Israel in, or vice versa. But they won't. Israel won't back down and the US won't be able to get out.
There could be ways for Trump he could cite unpopularity at home, or blame the whole thing on Israel, I don't know if he'd do any.