Oh, no, no, no, America is not a colonizer.
Before WWII, we were isolationists, hesitant to enter WWI until pressured into it by the bickering aristocrats of Europe and, again, hesitant to enter WWII until invaded by Imperial Japan, the country that bombed Pearl Harbor, causing the US to enter the war. After WWII, the US did not colonize the conquered territories. We pulled out of Europe and Japan, quickly, leaving them to govern themselves.
Due to fears of communist expansion, after WWII, the US spent boatloads of taxpayer money and lost countless men, fighting in foreign civil wars to prevent one side of a far-flung, foreign nation from being taken over by the communist-infested other side. This was a mistake, humbly admitted by many American leaders. But we pulled out of those countries; we did not colonize them.
In recent decades, we acted in alliance [with other countries] to prevent one Arab country from overtaking another Arab country in the Gulf War. We defended our nation when it was attacked by radical Islamic terrorists, a group of student visa holders treated very well in America that committed a mass murder of 3,000 American civilians on September 11, 2001. Did America’s leaders take it too far, extending a necessary, defensive military attack on Afghanistan, the country that harbored the mass-murdering terrorists, to other countries? Yes.
Nation building was a mistake. It does not work. It was not extensive enough or long enough in duration to be labeled colonization, however, AND, unlike the colonization pursued by other countries, the US did not seize the natural resources of the countries where it tried nation-building projects. A few US companies did made bank on the war clean-up, but the oil was left intact for the native populations.