The United States didn't join the fight against Germany until its merchant ships were attacked. America was isolationist then as it is now against Russia. Only when its self-interest is threatened will it act.
https://fortune.com/2022/03/13/nato-will-act-russia-hits-alliance-us/
"Leading up to the Second World War, much of Europe, especially Great Britain, subscribed to the policy of appeasement when it came to Germany's expansion, hoping that it would prevent further conflict and all out war.
Great Britain's Prime Minister Neville Chamberlain was particularly associated with the policy of appeasement and had continually made concessions to the ever expanding Germany and had asserted that there would be peace in Europe.
1938, Hitler started to make claims on parts of Czechoslovakia and was further appeased when the Munich Agreement was signed in September. This allowed Germany to claim parts of Czechoslovakia with permission from France and the United Kingdom.
February, 1940 Russian troops invade Finland on November 30th, and the USSR begins to bomb Helsinki."
During the build-up to the Second World War, the United States maintained neutrality with several formal Neutrality Acts. However, there were "cash and carry" policies that were put into place that allowed the US to sell arms and war materials to the United Kingdom and France. The United States remained neutral until 1941 when German ships began to attack US ships and the Japanese attack on Pearl Harbor."
What are we Americans missing here? Are we officially isolationists and allowing the world to be destroyed without our interference? The similarities as pointed out above are alarming.
America is a great deal different than when I was in Delta Force.
As is noted elsewhere here, Putin has little to fear from us given our embarrassing track record over the last decade.