Soldiers and police have killed over 200 million civilians this century. For every soldier killed in combat, more than two unarmed civilians were slaughtered in this, the bloodiest century in human history. But it gets worse. Three quarters of those dead civilians were killed outside of a combat zone, and most were killed by their own government. That's called democide. While it's not really a new development, it was never as big as it was in the 20th century. The major offenders have been; USSR (61 million killed), Communist Chinese (38 million), Nazi Germany (20 million), Nationalist Chinese (10 million), Imperial Japan (six million), Cambodian communists, two million), Ottoman Turks (1.8 million), Vietnam (1.6), Polish communists (1.5 million), Pakistan (1.5 million), Yugoslav communists (one million.) There are a number of surprises on this list. Most people think the Nazis were the worst offenders, but they are really only number three. That's because the communists managed to hide their mass murders for most of the century, aided by the tendency of the free world media to believe a lot of the propaganda regarding the "Worker's Paradise". Even before the Cold War ended, there was a growing pile of evidence that something very bad was happening behind the Iron Curtain. During the 1990s, scholars have been able to investigate the communist democides more thoroughly and now we know. Some of the smaller offenders on the list are hardly noticed at all, but this is because after World War II most people were sick and tired of war and the massive deaths that accompanied it. But in Eastern Europe, revenge was in the air. While a lot of fascists got killed, so did a lot of innocents. Even being suspected of anti-communist tendencies could get you killed back then.
Democides continue, and now they get a lot more attention. Figuring out how to stop them is another matter. But when the media jumps on a tragic situation like this, they often zap a few innocent bystanders as well. A good example is the recent news stories of the killing of South Korean civilians by US soldiers in 1950 near No Gun Ri. This incident, and many similar ones, have long been common knowledge to US soldiers who served during the Korean war, or later. It was a not uncommon practice for North Korean troops to wear civilian clothes and mix in with fleeing South Korean refugees in order to get behind US troops. This tactic was learned by the 100,000 North Koreans who had served with the Chinese Communist army during the Chinese civil war, and then transferred to the new North Korean army in the late 1940s. The Chinese Communists openly preached the use of guerilla war tactics during their war with Japanese and Chinese Nationalist forces from the 1920s to 1949. As a result, civilians were often fired on if they approached troops who feared (often from past experience) that there were armed enemy soldiers mixed in with the civilians. Americans learned of this tactic the hard way in the Summer of 1950, as they retreated before the advancing North Koreans. A similar tactic was used against UN peacekeepers in Somalia in the early 1990s. In one incident, 24 Pakistanis soldiers were killed. The same tactic was seen by US troops in the 1993 Mogadishu shoot out that killed 18 US rangers. In that fight, US troops quickly learned to either shoot at the civilians the gunmen were hiding behind, or get shot themselves.
Some two million Korean civilians were killed during the 1950-53 Korean war.
The Geneva Conventions do not prohibit the killing of civilians, recognizing that there is often what is termed "military necessity." If this were not the case, every nation involved in World War II would be liable for shelling or bombing civilians. There are cases where civilians are killed for no military reason, and these can be, and sometimes are, prosecuted.
The survivors of the No Gun Ri killings are demanding compensation from the US or South Korea for their suffering, arguing that there was no military necessity. Nearly five decades after the fact it is going to be difficult to change anyone's mind.
It has long been army policy not publicize incidents like this, or things like the high friendly fire rate among American troops (estimated to be as high as 20 percent of friendly casualties in some battles.) It's bad for morale. The troops don't like dwelling on the fact that in battle their own weapons sometimes kill friendly troops, or innocent civilians. The commander on the spot is in a no-win situation. If he does not order using fire to keep civilians (and enemy infiltrators) away from your troops, then he has to suffer losses to his own troops when the enemy infiltrators get behind friendly lines and begin ambushing American troops. This is especially the case during a retreat, which is when the No Gun Ri shootings took place. When the troops are in one place, they have more options to deal with masses of moving civilians. But during a retreat, when everyone is moving and you're not sure where the enemy will show up next, the tendency is to shoot first and check IDs later.