We should switch from being able to invade any country in 8 hours to a heavily more defensive doctrine. A defensive doctrine would be cheaper and more effective. Every able bodied citizen should be expected to contribute to defense in the event of invasion. Switzerland is a good model for this issue.
In the case that this is an American question, of course I support cutting spending. We are the most armed nation in the word. We can start winding it down. I can't see why anyone would want to mess with us if we had half the spending aside from the feuds we've fueled with "defense" spending.
There are many bases across the world that operate, draining money from the country's coffers and do not actually provide any benefit to the current state of the U.S. Military. Also, defence contractors, which are entirely not needed, drain millions from the government by unnecessary billing and over-inflating prices. By going through and overhauling defense spending, we can still maintain the size of the military we have without frivolous spending that could bring in income that could be used elsewhere.
The International Institute for Strategic Studies claims that in 2015, the US spent nearly 600 billion dollars on defense. The nearest second was China, at just $145 billion. We could cut our funding in half and still be far in the lead. With such low global rankings in education, happiness, liberty and health, I feel that it would be much wiser to use the money to help alleviate some of these problems.
I don't think terror was the issue it was fifteen years ago. Plus, our country is in debt so we should be cutting where we can, especially in areas where the public wont be effected directly. I don't think I would ever support spending cuts on welfare or social programs, but I do support defence spending cutting.
First and foremost we need to understand that the defense spending of the United States is greater than the next 7 countries on the list of defense spending by country. Even cutting the defense spending of the United States by one half and the United States would still be spending more than any country in the world for defense. So in this instance that should show that the United States as a whole would be safe in cutting spending a bit.