I could go and explain that we have a global economy built largely on the capitalist ideals and free enterprise system that the US was built on. I could tell you that in this day and age there are not enough of us in this country to sustain our economy if we were to cut ourselves off and our success in trade is only being impeded by our crazy labor laws and the insane salaries that have evolved due to unions. I could also explain that protecting our allies also protects our customers as well as those who bring us goods and services, that since we won’t develop our resources here by protecting our foreign supplies of oil and other materials we prevent our economy from grinding to a halt, however in this case it would be a waste of time...
So we pay trillions for defense to protect whom exactly?