If that wasn't an act of war against the USA in the 1960s, then whatever the Russian are saying it is now is hyperbole.
So we can send 2 1/2 million men 10,000 miles, get 56,000 of them killed, kill countless locals and ravage 3 countries for a decade to prevent the first domino from falling. But the Russians can’t react when the largest offensive military machine in history is sitting on their border, a days tank ride from Moscow, screaming forced regime change in Russia? To date, 16 dominoes have fallen and Ukraine is the very last one and it is falling. I have two words for you, FRiend, Alas Babylon!