@nimh,
There is a major flaw in your thesis here. The United States did not "intervene" in World War II. The Euro-centric view is that the second world war began in 1939, with the German invasion of Poland. A good case can be made---I have made in these fora before--that the second world war began in 1937 at the beginning of the Second Sino-Japanese War. That war saw Japan not only invade China, but engage the Soviet Union in Mongolia, and significantly, to bomb the American gunboat
Panay in the Yangtse River at Nanking (now called Nanjing) at the time of the event known as the rape of Nanking. The Japanese did not want American intervention, so they publicly apologized (something very humiliating for them) and they paid reparations.
Even if one simply focuses on Germany's military adventurism in Europe, the United States did not enter that war until Germany declared war on the United States,
after the Japanese attack on Hawaii. It is also a bit rich to see any European sitting in judgment of the United States given that the world still suffers from the consequences of European colonialism more than fifty years after most of those colonies were lost or given up. The Dutch were not behind hand in that colonialism, and began in 1595 in the spice trade from Java. In 1602, all the Dutch efforts were consolidated under what in English is called the Dutch East India Company. They were as ambitious as any of their neighbors, too. They set up a colony in North America in 1624, and overran and took over the Swedish colony on the Atlantic coast of North America, before the Duke of York took New Amsterdam away from them.
Rather than continuing the list of Dutch enormities, I will just say that the hypocrisy of Europeans who complain about American interventions is disgusting. They were happy enough to see the United States intervene in Europe, and happy enough to see the United States take over the role of international policeman after 1945. How convenient for them that they now have the United States to blame and scold as the consequences of European colonialism continue to plague the globe.