Not a single NATO partner has consistently met the 2% GDP spend mandate historically outside the US. The US spends aorund 50-60B a year for our 40+ bases in europe. But this is offset by nato expenditures. For example, Germany gives us a $1B a year for our bases.
Remember, part of being in NATO is the requirement to spend a % of your GDP on your own military, which the US will do regardless.