And pretty soon you're talking about real money

How much does the United States spend each year occupying the planet with its bases and troops? How much does it spend on its global presence? Forced by Congress to account for its spending overseas, the Pentagon has put that figure at $22.1 billion a year. It turns out that even a conservative estimate of the true costs of garrisoning the globe comes to an annual total of about $170 billion. In fact, it may be considerably higher. Since the onset of “the Global War on Terror” in 2001, the total cost for our garrisoning policies, for our presence abroad, has probably reached $1.8 trillion to $2.1 trillion.

The Nation