America spends a lot of money on defense. There are reasons for that (and I didn't even mention that we maintain reserve stocks of ammo and spare parts that allies rely on), which mean that our military capacity isn't as large as a simple money comparison with potential foes implies. If so, South Vietnam would exist, for example.
But one thing thing that really bugs me is that opponents of military spending like to point out the top X defense spenders and say that the overwhelming number of them are our allies. So why do we spend so much money on defense?
The summary of the new national defense strategy gets at why this is so:
Mutually beneficial alliances and partnerships are crucial to our strategy, providing a durable, asymmetric strategic advantage that no competitor or rival can match. This approach has served the United States well, in peace and war, for the past 75 years.
The existence of all those allies willing to fight with us or at least cooperate with us magnifies our defense capacity while denying potential foes allies.
I've noted this explicitly in regard to China's rising power and regional allies in the western Pacific, but it applies generally.
If we don't spend on defense to create decisive military power capable of reaching distant regions where our allies are, over time--despite common interests in democracy that you'd wrongly think bind us forever--those allies would drift to neutrality and some would even become allies of our nearby foes who can defeat our allies because America can't provide the margin of victory needed to win.
Knowledge that America is a friend and can extend our power to help defend them keeps allies with us.
Spending enough on defense to keep our alliance network intact is a wise investment. If we ever fail to do that, we will find that having Eurasia and Africa dominated by foes and their allies or clients would require America to spend a lot more to defend the Western Hemisphere. Each ally that goes neutral would require America to make up for that spending loss; and every ally that joins our foes would require America to make up for the loss of spending and counter the addition of spending to our foe's side.
The loss of overseas bases would also add to our military costs if we hoped to fight over there rather than over here.
And we would likely not be able to afford that because the world economy would be organized in ways that favor those who dominate the Old World rather than America and our allies.
