Because it is a very string, stark, emotive word. It carries a lot of weight even sub-consciously, and makes it easier to get taken seriously (or taken as right). It makes it personal. Not just "something that could do to be fixed", or "right vs wrong" - it means "us vs them".

may be so, but when it is overused, it loses it's seriousness, no?

To an extent yes, though I think it is a concept that registers quite deep to the point where our reaction is at least partly instinctual (the old fight/flight response) to it'll not become totally ineffective.

I was shocked when I worked in America at a kids summer camp, and every activity/game was "war this" and "war that".

Kids in America are quite literally taught to go to war at every possible juncture, like it's a valid way to solve some conflict.

As a visitor to the US I noticed a version of this in small ways - shops selling things cheap to servicemen/woman, statements praising the military on buildings, headlines about military gains in papers, people in uniform all over the place etc. If I didn't know better I'd have assumed America was defending itself against a perilous onslaught.

Well, even the members of the U.S. military tend to find that over-the-top, it's not just you.

I don't remember being taught that.

Edited to add: don't get me wrong, I'm not claiming you're lying, just that your experience doesn't necessarily generalize.

That's the scary part.

You also don't realize that swearing allegiance to a country is a very, very bizarre and backwards thing to be doing. The rest of the developed world is shocked by this practice, but you were taught so young you don't even know it's strange and wrong.

My country has a "swearing the flag" routine, and it used to ask for a certificate of allegiance for bureaucratic procedures... it's a remnant from the dictatorship in the 70s.

In Canada when someone takes an the oath of citizenship they still swear an allegiance to the monarchy. I think there is a similar component for elected officials and people in the military. That has always struck me as bizarre.

That's a strange interpretation of my statement. Let me be slightly clearer: I don't think children in my community were/are taught that. To be fair, I grew up in hippieville, but nonetheless.

It's part of the US propaganda machine. "War" is used to rally the population against something evil...an outside force that must be stopped.