Opposition to American imperialism isn't support for Russian imperialism.

The simple truth is that this prolonged war is worse than a quick defeat for the people living in Ukraine; millions are displaced, hundreds of thousands are dead, the rightwing is stronger than ever in both countries, and Ukraine will never be safe again within either of our lifetimes.

3 parties can unilaterally end the war right now, Russia, Ukraine, and America. As an American, the only way I can meaningfully oppose the war is to oppose America's involvement. That would be reversed if I was a Russian.