Do you think the Soviets should have run around slapping random people who used to be in the Wehrmacht? Do you think throwing your milkshake at some German who supported Hitler in 1932 would have stopped the Nazis?
Punching random goons achieves nothing for the people. It is not praxis, it is not a revolutionary action, and saying you support it doesn't suggest that you take actual steps to oppose anyone.
NATO is a military organisation which is led by the United States. The war started from expansion threats by NATO against Russia; or in other words, the war is NATO vs. Russia.
As NATO is and long has been led by the USA, the Commander-in-Chief of the USA speaks for them.
(As for why, if it's NATO vs. Russia, NATO haven't gone all-in? Because they could very easily start World War III that way, and no one is very keen on doing that.
Oh, and also because they don't give a fuck about East Slavs.)