The cost to being the world's superpower is high. But like divorce, it costs a lot because it's worth it.
How about putting some meat on that bone? It's worth it? Prove it.
Britain and France slashed defense spending in the 1930s while Germany re-armed. We see the result of that. The U.S. maintained high spending through the Soviet era and we see how that worked out.
I realize you don't understand the points I just made and will make some insipid comment but there you have it. We have not had a world war since 1945 and U.S. military power is the reason.