War is brutal. It makes people do harsh things. Then, it makes the other side retaliate against those harsh things. But war is also a fight with rules and when sides don't play by those rules, tempers flare, emotions run high, and that's when the sh*t really starts to fly.
Now, the third Geneva Convention governs the treatment of POWs. No POW can be tried for fighting in war, though they can be tried for war crimes — but they certainly aren't supposed to be executed immediately. Unfortunately, not everyone follows the laws of armed conflict like they should.
The following 7 troops would be executed immediately after capture.
7. Anyone with a trench gun.
During WWI, American troops used what came to be known as a "trench broom," a Winchester model 1987, modified for trench warfare. The rifle fired buckshot pellets and could be slamfired, meaning if the user holds the trigger as he pumps a new round in the chamber, the round will fire automatically. Needless to say, the trench broom killed a lot of Germans.
When you need to get that pork sausage smell out of your trench.
The Germans lodged a formal protest against the use of the weapon, saying it was illegal under the 1907 Hague Convention definition of any "arms, projections, or materials calculated to cause unnecessary suffering." When the American continued using it, the German High Command threatened that any POW found with a trench gun or trench gun shells would be shot on site.
6. Germans with flamethrowers.
General John Pershing didn't get to be the highest-ranking military officer for life because he took sh*t from people that were trying to kill him. When Germany issued the aforementioned decree, Pershing declared that any German with a flamethrower or saw-bladed bayonet would be shot.
No one on either side was shot for these reasons. Pershing 1, Germans 0.
A tradition that would continue into the subsequent World War.
5. WWII-era special operations commandos.
Hitler was so pissed after he heard the German commandos on the island of Sark were found with their hands tied up and shot that he ordered any commando caught by the Nazis to be interrogated and then immediately executed. He specifically mentioned that it didn't matter if they were armed, in uniform, military, or civilian — their lives would all end the same way: with a bullet.
Which is how Hitler would meet his end.
4. Soviet commissars.
This one's another Hitler order. The man was not a fan of Communism and so issued the "Commissar Order," which stated that Soviet political officers captured on the Eastern Front would be separated from their units and executed. He believed their sole purposed was to spread "Judeo-Bolshevism" and that they needed to be eradicated.
Except the Russians really blazed new trails in murdering Jewish people, too.
The order extended to anyone in the Soviet service who either bought into Bolshevism or was there to spread the ideology.
Countries don't like it when soldiers only fight for money. You at least need to have a flag to which you pledge your allegiance. It doesn't matter if you're an American — if you're not fighting with the American army, you better not get captured.
In 1976, four mercenaries – including one American Vietnam veteran who was recruited in Soldier of Fortune Magazine — were captured fighting against the government in Angola's civil war. When captured, then-President Agostinho Neto ordered their execution, ignoring clemency pleas from the Pope, Queen Elizabeth, and Henry Kissinger.
A lot of paid mercenaries fought in Africa in the 1970s from all over the world.
The Confederate Army in the U.S. Civil War would also execute civilians caught fighting in Civil War battles, whether they were paid or not.
2. Pretty much anyone with a flamethrower.
The flamethrower was a nasty weapon. If I were a troop where facing a flamethrower was a possibility, I'd be scared sh*tless, too. But the flamethrower guy didn't ask to be given the flamethrower. I mean, I assume... who's going to ask to carry around a very shootable tank full of explosively flammable liquid that only gives you about six or seven seconds of firepower?
A good reason no one wants to be your friend.
There's no "stop drop and roll" when you're covered in napalm. So, it was pretty well-known that every side hated you so much they would shoot you just for being the guy with the flamethrower. For the Nazis, this extended to flamethrower tank crews.
1. The Waffen SS.
It was not an official order, but among the Allied ground troops, there is a ton of anecdotal evidence that captured Waffen SS members were usually "shot while trying to escape."
At least give the enlisted corps a five-second head start.
The Russians hated them because they found many of their Eastern Front POWs in concentration camps, shot or slowly worked to death. The Canadians hated the SS for the Ardennes Abbey Massacre. The SS slaughtered American POWs at Malmedy during the Battle of the Bulge. British and French POWs were massacred numerous times by Waffen SS troops.