If two countries go to war, how can the opposing army know which army is theirs without accidently shooting their own teammates?

Question

Does every army in every country have a different uniform? Or do they all wear camouflaged suits or something.

In: 729

Answer 1

Reminds me of the movie Saving Private Ryan, there was a scene where the protanonists were running through a small French village during ww2. They were then spotted by a small group of ally soldiers that yelled out “thunder!” They then responded back with “flash!”. They obviously circulated commucation that would be their codeword for the day / week / month or whatever. Supposedly, in German these words to difficult to pronounce, hence they would be able to hear a faker easily.
In another scene, the same group of allies runs across town and suspect that someone is out there around the corner. They yell the same “thunder” repeatedly, until the commanding officer says “thunder or we will fire on you”.
They will obviously not fire on civilians, and is their duty to make sure of that first.