Okay then. There are some conspiracy theories about the attack on Pearl Harbor. However they have been discounted. It really makes no sense that FDR would have allowed an attack to cripple the Pacific Fleet and jeapordize that theater of War. The US and FDR'S Administration felt Japan was the lesser of the threats when compared to Nazi Germany. And the Philippines were considered a more probable target for a Japanese attack.
The Maine incident has been proven to have been caused by an explosion in a coal bunker adjacent to the magazine. The Declaration of war was fanned by the Yellow Journalist's of the time. It did however take little to convince the American public that Spain was at fault (although they were not) US papers had been covering the maltreatment of Cubans for some time prior to Maine being sent on it's show the flag mission.
As far as the submarine incident in Vietnam. I assume your talking about the North Vietnamese torpedo boat harassment of a Destroyer in the Gulf of Tonkin. Referred to as the Gulf of Tonkin incident. The US was already engaged in advisory and support of the Republic of Vietnam at the time. The molesting of an American Vessel only elevated the level of conflict it did not kick off the conflict .
The WMD's in Iraq have been discussed at great length here already. My stand on that issue is it was a failure of intelligence and a by product of giving Sadaam too much advance warning. But regardless of whether or not WMD's were found Sadaam is no longer murdering, raping and torturing his own people.
There was also another powerful empire who according to your thinnly veiled accustations kinda of meets the criteria you have set.They invaded and stripped countries of their wealth and enslaved people of the countries and eradicated or attempted to eradicate the culture and religion of the people. Their Generals were thought of as Great Soliders and Explorers, Statues were erected of them and many still stand today. Cities and streets were named after them. You know Desoto, Cortez, Pizzaro