It's easy to say that in hindsight, the problem is due to economics/etc we weren't in any position to move against Hitler prior to WW2 (hell we weren't even in a good position then hence Dunkirk). Hence why we appeased him to buy time to prepare for the inevitable war (same reason Stalin agreed to split Poland with him).
Not quite correct. The Germans did begin covertly rearming after 1918, in violation of the Treaty of Versailles. However, during the period of the Weimar Republic the German economy was very weak (hyperinflation and political instability) so they were limited in how rapidly they could rearm. When Hitler came to power in 1933 he openly and massively expanded German rearmament. In the same year, Hitler withdrew Germany from the League of Nations and the World Disarmament Conference making his intentions clear. Frankly, the fact that he had explicitly stated the years by which he intended to have conquered each European country in
Mein Kampf (published in 1925) should have made his removal ASAP a priority anyway.
Stalin had initially tried to make a military alliance with the UK/France with a view to fighting Nazi Germany alongside us, but he was rebuffed. He believed (probably correctly) that our policy was to encourage Nazi aggression in Eastern Europe which would result in Germany and the USSR going to war and destroying each other, so he negotiated the Molotov-Ribbentrop non-aggression pact with Hitler.
With the help of the USSR the Western WW1 allies could have dealt with Hitler when he came to power in 1933. If our ruling classes had not ignored the threat from Germany (
due to their greater fear of Soviet Communism) and failed to rearm all the way through the 1920s, when our economies were strong, then they could have finished off the Nazis without Stalin's help. Of course, after wiping out the Nazis we would have had to worry about Soviet aggression against Western Europe (since they would not have sustained such devastating losses during WW2).
The lesson of World War 2 is do not ignore an emerging threat or hope that you can spin your enemies off against each other. I hope we will not make the same mistake with Putin. While Putin's forces are tied up fighting the Ukrainians (who deserve our unwavering support) we should be rearming and deploying conventional forces along with tactical nuclear weapons to the Eastern European NATO member states. If Russia sees that NATO has powerful forces along their European border they will be deterred from attacking vulnerable NATO members. However, if we repeat the defence policy blunders of the 1920s and 30s (and Trump simultaneously removes US support from Eastern European NATO members) then we should expect serious Russian aggression.
