I hear some candidates wanting to declare war on our enemies once in?
For the United States to go to war on at the whim of some snarling jingo would cause a worldwide financial panic and probably drop the value of the American economy by trillions of dollars over the course of the first view days. It would also bring on a political crisis that would further erode confidence in the dollar and cost the United States even more trillions. The direct cost of waging a war against a foreign country depends entirely on which country the United States attacks and what its goals were. It would be a small number by comparison. The last time this happened, with Iraq in 2003, the cowards in charge of the Bush/Cheney administration refused to pay for the war at all. They had already instituted tax cuts for their wealthiest followers and token cuts for their voters and let the entire cost of the war and occupation pour into the American national debt. At no point during the next five years did anyone but a few established liberal democrats in the congress question this action. It never became part of the political discourse because the republicans, their conservative democratic allies, and their media base decided that it was not important.