"Why is our take on another country's election OK"?
Oh, that's an easy one.
We have moral authority. We have 200 years' experience at this. We have spilled an enormous amount of blood for freedom. And not least, there was very serious election fraud in Ukraine. The fears of Republican "election fraud" were nonsense.
Major differences in the two situations, I'd say.
I shudder to think how the Cold War would have turned out if, say, President Reagan had taken your simplistic, isolationist line back in the 1970s and '80s.
Perhaps you also think we should apologize to the Iraqi people for interfering in their country? That's what you sound like.
You don't know that. What we ought to know is why we do what we do. Moral authority? Not in the last 40 years.