I think it’s important to understand that Marxist-Leninists should be supporting the people of both countries, rather than picking one of two capitalist states to back. I understand that Russia has its excuses for doing this, and the Ukraine government has its excuses for what it has done, but it’s important to remember that they are both capitalist countries in the age of imperialism; what they are really after is power. Please feel free to correct me if you believe I got anything wrong.
Saying that “the American Empire must be destroyed” sounds very idealistic to me. In a more materialist perspective, I would say that the empire is already in a strong decline (in large part caused by itself). The intention of Russia and China seems to be managing that decline in a way that protects themselves and others, like avoiding a nuclear war. So far they seem to do a good job.
Other than that, I fully agree with you.
I think it is obvious that Russia’s action in Ukraine is the consequence of Anerican decline. And not the other way around.