When talking about the U.S., people refer to it as "the land of the free" or as a beacon of democracy and liberty. Thanks to them, many disasters like a nuclear holocaust and Saddam Hussein's massacre of his population were avoided or, at least, lessened ... of course, let's quiet down the fact that Saddam used to be a U.S. ally against Iran.
But if the U.S. can give itself permission to intervene in other countries' internal affairs to stop questionable actions from their governments or to stop other countries from aggression, surely other countries could have done the same. Just look at these 11 historical examples of U.S. authorities killing many people or violating their sovereignty:
As more and more Eastern settlers moved westward, local natives were getting upset as their homes and food supplies were getting disrupted. Many of them attacked those settlers, but U.S. authorities responded with disproportionate force, like this tragedy in modern-day Idaho where hundreds of Shoshones were massacred. Soldiers killed most people in sight and raped women or killed them if they resisted.
This 1864 atrocity was another episode in the U.S. conquest of so-called Indian territory, despite previous treaties recognizing that they owned the land. Because of a local gold rush, their territory shrank more and more until they were left with a land less than 10% its original size. Because a few more ... assertive Cheyenne attacked white settlers, 70 to 163 civilians, mostly children and women, were massacred in Sand Creek, in modern-day Colorado.
Yet another episodes of "natives greatly disadvantaged by a treaty and yet are accused of all wrongdoings." This time, it involved the killings of anywhere between 13 and 150 Natives in present-day Oklahoma.
This was the last battle of the Indian War. As U.S. troops were trying to "gently" disarm Lakota natives in South Dakota, some of them resisted, which started the gunshots. Between 150 and 300 Lakotas were killed during this tragedy.
During these events, 19 striking miners, mostly of Eastern European origins, were shot in the back by a local sheriff and his men. They were acquitted of any crimes, showing that the state can't accuse itself.
This is the worst killing to have happened in Puerto Rico, a territory under U.S. jurisdiction. Blame was put on U.S. authorities and their appointee to the island, Blanton Wintee. Neither he nor anyone under his command was prosecuted or reprimanded for the killing of at least 19 Pacific marchers.
The U.S. and her allies went to Korea supposedly to liberate the South from an invasion of the communist North. It didn't stop Uncle Sam from killing at least 163 South Korean refugees. The Pentagon has been accused of whitewashing in this affair, as it refused apologies or compensation for survivors.
This event was one of the reasons the Vietnam war grew very unpopular. Thinking they were facing North Vietnamese troops they were "fighting", U.S. soldiers massacred at least 350 South Vietnamese civilians (whom they were supposed to protect from the communist North); they also committed mutilations and rapes. The biggest sentence in this tragedy was three and a half years of house arrest to a platoon leader.
Not unrelated to the events of the preceding massacre, this killing, perpetrated by the Ohio National Guards, killed four unarmed, peaceful protesters and injured nine others. Anti-war protesters were seen as anti-American and bound to destroy the city and higher education in Ohio.
Apparently used as a retaliation to the previous bombing of a Marine convoy, U.S. troops shot 24 unarmed civilians. As with previous cases, no serious charges were retained against the Marines involved in the tragedy.