Capital flows between groups is an interesting way to look at it, but it doesn't consider efficiency of what money is used for, invested in, spent on. You coul

Capital flows between groups is an interesting way to look at it, but it doesn't consider efficiency of what money is used for, invested in, spent on. You could have identical capital inflows and outflows (i.e. money coming in to the US from the international community) but it could be wasted on things it shouldn't. 3% of GDP is very reasonable unless extreme circumstances were present. In that case, politicians might just have to resign after their term.