Iran, and likely all major US adversaries now, were/are fully prepared for the US assassinations. And gaining full air superiority is no longer possible in the era of drones, because you're no longer shooting down a small number of high value targets (like planes), but instead a practically infinite amount of low value targets that can be readily replenished.
Spending interceptors that cost millions of dollars to shoot down drones that cost thousands of dollars just doesn't work. We might be able to obtain air superiority in terms of e.g. Iran being unable to fly fighter jets over their own country, but that says nothing about their ability to launch endless drones and otherwise inflict a severe toll on any invading army.
So it's likely that modern war has mostly gone back to times long since past where the bottleneck is no longer cost in $$, but cost in lives. And that makes militarism far less attractive for every single country, even moreso in the era of plummeting fertility rates when the people who are going to be killed are precisely those who are supposed to be birthing and raising your next generation.
So there will certainly be wars when nations see the benefit as being especially high, but I think the idea of trying to casually 'project strength' half way around the globe is probably already dead. The cost is too high, and the benefit too low.