I mean if Russia can just walk into Ukraine, why can't Israel terrorize Iran from the sky. Why can't China just waltz into Taiwan?
The thing about Trump's isolationism is that it's actually a passive aggressive position. Imagine you know which kids in your classroom are likely to fight and you take a policy of "I won't stop it if it happens", that's basically telling some of the kids "go ahead", so how is this isolationist?
Now, literally joining in on the fight when the kids pop off, that is uniquely Trumpian.