Here's a description of spending over time - adjusted for inflation.
We are spending more now than we have in at least 50 years - it would be nice if the graph went back through WW2 at least. Believe it or not, after the end of the Cold War, people spoke of the peace dividend since a large military was no longer needed - but notice the impact of 9-11.
This graphs shows US military spending compared to that in the next nine nations in the top ten:
We spend considerably more than the next nine combined, and likely more than the rest of the world along with it. The question is whether this is necessary to secure the nation, or just pork. A reward for well connected military contractors and jobs for people in key congressional districts.
One argument in favor of having the dominant military in the world is that it helps cement the US's economic dominance as well. We own both the seas and space. That does contain dividends.
