@hamy,
hamy wrote:pearl harbour introduced the usa 2 years late in ww2.
Yes and we were "three years late" (by your measure) getting into WWI as well. Both actions were mistakes. We had no interest whatever in who won the struggle for dominance in Europe early in the 20th century, and the underlying competition for colonies and expanded empire that was behind it all.
One of the many unhappy results of WWI was Britain's use of Japan to (as they imagined it) have the Japanese Navy take the German island colonies in the Pacific and help suppress German naval operations there. This was done despite contemporary U.S. objections. The result was the start of the Japanese Pacific Empire that later took Hong Kong, Singapore and Malaya from Britain and attacked us at Pearl Harbor.
Another unhappy direct result of British & French colonial campaigns in WWI was the destabliizing of the Islamic world and the development of Islamist fanaticism there. We are still dealing with that mess.
Vietnam was in part our own mistake. After defeating Japan and negotiating the removal of their army from Vietnam we should have prevented the French colonial masters from returning. However we were distracted by concerns with the Soviet Union and the then ongoing struggle in China, as well as political struggles between left and right in France.
Perhaps I have lost sight of the theme of this thread. Was it "why are Europeans so greedy, ignorant and hypocritical or was it .....