what was the major western power after world war i

Determining a single “major western power” after World War I is a bit nuanced, but there are two strong contenders:

The United States: The US emerged from the war largely unscathed and with a significantly strengthened military and economy. They played a major role in the war effort, particularly in the later stages, and their financial contributions were crucial to the Allied victory. However, the US also remained somewhat isolationist after the war, and their political influence wasn’t as dominant as the European powers.

Great Britain: Though severely impacted by the war, Britain remained a major power with a vast global empire. They played a central role in the war effort throughout, and their leadership on the Western Front was significant. However, Britain’s economic and military strength were undeniably diminished after the war.