For example, forty years after the last U.S. combat troops left Viet Nam, the government is still paying veterans and their families more than $22 billion a year in war-related claims.
Perpetual warfare is a dubious luxury we can no longer afford.
We never could really afford it, but unfortunately it proved impossible to live on the same planet as Adolf Hitler and the Japanese military. Beating them required the full mobilization of society, for it was total war. The US role as "arsenal of democracy" or supplier of weapons and materiél as the essential element in the allied plan worked well.
Now we're stuck wth it. The economy of this country can't function unless we're at war or preparing for war. The price we pay needs to be accounted for in a lot more than just money.
First of all, it has led to habitual belligerence, so that the Uncle Sam, rather than Hitler or Tojo, is now that SOB the rest of the world can't live with.
Secondly, being always at war and having a thousand or so overseas bases from which to wage it means we have become an empire now. I don't remember when the people voted that their country should become an empire. If they had, they might have reflected on the choice between empire and democracy, cause you can have one or the other but not both.