In Canada we are taught that due to their isolationism, the US had a very small role in WW1, with for example, a late entry and fewer combat casualties than Canada despite a much larger population. We are taught about the Zimmerman telegram and the Lusitania being the main triggers.
We are taught that the US remained isolationist after that, being very reluctant to enter WW2 and in the end only joining about 2 years after it "started".
For Commonwealth countries, the war began with Germany's invasion of Poland in 1939. For the Czech Republic, it started in 1938. In parts of Asia, the war began even before that, with Japanese aggression. For some countries in the middle east, WW1 never really ended. But we can all agree that the Americans were pretty late to the party and it's weird when you hear them say that "WW2 began toward the end of 1941 with Pearl harbor", at which point much of Europe was already being crushed by the Nazis.
The US viewed the initial years of WW1 as an European war and there was little appetite to become involved in spite of the cultural connections between the US and France and the UK (and Italy and Russia to a lesser extent.)
For the reasons cited elsewhere in this thread, the US did declare war in April of 1917 but, starting with a very small full time army, it wasn't until early 1918 that the buildup of US forces was significant. Over 2 million men and women had arrived in France by the summer of 1918. While there were several divisions that fought with the British and Australians most of the US campaigns were in various parts of the French sectors which tend to be, in my opinion, overlooked or minimized by UK historians. Significant actions included the 2nd Battle of the Marne, the Asine Marne campaign to reduce that salient, the reduction of the St.Mihiel salient, and the Muse Argonne offensive in which over 27,000 Americans lost their lives. For having only part of a year in significant combat the US lost a little over 53,000 battle deaths and another >60,000 to disease including a significant number to the Influenza Pandemic.
Some historians argue that the entry of the US into the war and the campaigns the US was involved, often in joint action with the French, in addition to the UK / Commonwealth campaigns of 1918, in served to push the Germans to the point of collapse in 1918 when the general expectation of the allied leadership was that it would take until 1919 to force the Germans out of the territories they occupied.
Growing up in Canada, I was taught that the US entered WW2 well after Canada, and it was inferred that Canada stood up against Hitler before the US.
Then I read about the Canadian Conscription Crisis (WW2)[1] and learned that MacKenzie King was very opposed to going to war and preferred appeasement. His rationale was understandable - it was basically that any war would result in massive upheaval across the world, including Canada, particularly straining English-French relationships (as it did in WW1).
Canada ended up sending a volunteer division early on, comprised almost of entirely of English speakers. The French army ended up being called "Zombies" - trained, but never deployed. The one English division was run ragged - huge amounts of PTSD since they couldn't be relieved (there were no other soldiers to replace them).
Of course, conscription was eventually pursued (after a referendum) and Canada played a very large role in the European theatre. But the first few years were quite the cluster.
Between Dunkirk and Barbarossa Britain stood alone against Germany. Churchill’s “Blood, sweat, toil and tears” speech is a speech from a guy who is losing badly and has no illusions about it. The smart money on both sides of the Atlantic said it was hopeless and only an idiot wouldn’t sue for peace. Despite his many shortcomings, Churchill’s leadership was astonishing.
We are taught that the US remained isolationist after that, being very reluctant to enter WW2 and in the end only joining about 2 years after it "started".
For Commonwealth countries, the war began with Germany's invasion of Poland in 1939. For the Czech Republic, it started in 1938. In parts of Asia, the war began even before that, with Japanese aggression. For some countries in the middle east, WW1 never really ended. But we can all agree that the Americans were pretty late to the party and it's weird when you hear them say that "WW2 began toward the end of 1941 with Pearl harbor", at which point much of Europe was already being crushed by the Nazis.