It's because we are americans... We don't loose a war. We may not win, but we don't loose.
So anytime politicians want a never ending cesspool of spending, or a mobilizing force to get the electorate motivated to vote, it has to be a "war". One with now way to win is even better.
We are a war like people. We fetishize war. WHole families are defined by war of one type or another. It has been the corner stone of our nations economy since the civil war, and the corner stone of the media since the spanish american war. Our leaders are birthed from the struggles of it, actual or simply social. Our entertainment looks longly on the "great" periods of war, forgets the bad times.
Sports is war. Chess is war. Our childhoods are defined by "war". Everything from dodgeball, to video games is a competition, a battle to determine who is "the best".
Peace is for pussies, make war.
America, blowing shit up since day one.