Two issues here. The first is your use of an evil word - "budget." A budget implies someone is actually worrying about revenues and expenses. In 2020 the USA had a revenue of $3.42 Trillion. Out of that we paid expenses of $6.55 Trillion.
Wait...? What??? Yes, we spent $3.13 Trillion more than we took in.
So in the long run it is inevitable that our military will need to reduce massively in size as we can no longer support it. We cannot have the strongest military on earth without having the strongest economy on earth. And our economy is doomed with continued deficit spending. By the way, republicans are just as bad as democrats on this issue. They talk tough when not in power, but when given the power elected republicans are just as drunk and stupid as democrats. In my opinion, this is NOT a party thing. They each waste money, just on different crap.
The second issue isn't just incompetent leaders, but incompetent citizens. EVERYONE loves living on the .gov money, without realizing we don't need thousands of military contracts all over our nation! Every plane, tank, ship, etc probably has all of its parts made in about 80% of the districts, so no elected official wants to vote against cutting jobs in their own back yard. This isn't just the military's fault, but that of the elected officials and the citizens who pick them.
Final note: the largest place we could cut spending that isn't legally required by law? Yes, the military.
Regards,
Doug
PS - I am with you! I would cut military spending by 50%, to start.
Yeah it's funny how republicans preach fiscal responsibility, and then we get into military funding and they run like cockroaches from a light.