I know there's a sizable cohort of online people in the west who are convicted of the idea that Israel exists solely as a US proxy and is held in check only by Iran, but obviously no. Israel --- leave aside all the moral stuff right now --- is a hypercapable advanced high-state-capacity regional nuclear power with an extremely effective military. If they didn't buy arms from us, they'd buy them from someone we liked less.

Iran, on the other hand, partly as a result of Khomeinism and the status quo ante of the Iranian Revolution, when the military was a big part of the repression apparatus in the Shah's state, has more or less gutted its official military service branches. As we just saw, Israel literally controls Iran's own airspace. They flew slow drones over Tehran, presumably just as a "fuck you". Iran placed a huge bet on projecting military force through regional proxies --- the "Axis of Resistance". What they have instead of a modern military is the IRGC. See how that went for them!