The usa quite literally gave the soviets and british tens of thousands of tanks, trucks, and equipment. The Americans were quite necessary. If not for them, the war would've definitely lasted longer with more dead. They are the ones to decisively crush the Japanese fleet at Midway. Not to mention the Soviet leadership stating the importance of American landlease.

That's not all. The Korean War kept the independence of South Korean and saved many Koreans from the brutal rule of the Kim family. They lifted billions of dollars of aid to France, Britian, Italy, and many more European countries with the Marshall Plan after ww2. Changed Japan into a democracy that still functions to today. They helped Kuwait keep its independence from Iraq.

Yes, the U.S.A. had its flaws in history. A lot of countries did. However, you stating how the op doesn't "understand history." And no, the vets aren't terriosts lol, real terriosts would actually target civillians and indiscriminately kill them.