I think I can explain it but it is not going to really make much sense...basically because as you have already noted "making sense" does not have much to do with it.

The United States spends at least twice as much or many times more on defense than any other country in the world. This is because the United States really is playing the part of world police...for a number of reasons.

No other country is ever going to spend anywhere near what the United States spends on policing the world...not going to happen...and so to certain people in the United States this means we hold a rather large chip at the bargaining table.

Most countries, I believe, do not mind that we hold this chip because it means they won't ever have to go crazy spending on defense. The United States has made warring with other countries a profitable business and so it now is just a giant part of our economy. This works to the advantage of everybody...countries can spend far less on defense and blame the United States for bombing everybody they could give two shits that we bomb...because they don't have to do the bombing. So, they get both a bad guy to blame and they can spend their money on improving things for their people...if we are talking about first world countries and not theocracies or dictatorships...then all bets are off. The United States gets the big bargaining chip and they dump all kinds of cash into the defense industry creating jobs.

It's win-win all around as long as nobody minds that a lot of people have to suffer and die on a regular basis.

So, now we end up with a guy like Donald Trump as president. He points out the fact that everybody spends less than the United States on defense. He's not wrong on that but he also is not pointing it out to make anything better for anybody.

He points it out to create mayhem and play the blame game with his supporters who just want to blame somebody for anything they can blame them for.

It would make sense if Trump pointed it out with the idea that the United States was going to cut our absolutely insane defense budget and spend that money on making things better for the people of the United States. To use the funds for healthcare for all, dump the money into social security, fund education in this country...but none of that will ever happen under scum like Trump or the people that work to make our populace ignorant.

No...if other countries spend more on defense that means we have to spend more on defense.

Yes, it is with this idea that other countries buy more of the crap we pour insane amounts of R&D money into...whether it works or not. We can sell other countries the junk and keep dumping more and more into R&D.

If it meant that we would pledge that the United States would slash defense spending if our allies spent more on defense, GREAT!

Problem is we will never do that. So, Trump can correctly point out that nobody spends as much as the United States...which his idiotic base will embrace...but he only points it out so we can spend more. The filth here wants in excess of trillion dollar defense budgets...other countries have to help us pay for that...and they can help us by spending more on defense.

Yes, it is all totally idiotic and makes no goddamn sense...but this is our primary export now and Trump is pissing all over our allies and building up our enemies for specifically this purpose.

I wish his "base" here would see it but they don't. They buy into his insane rhetoric and see people from any other country as "invaders" and think these truly idiotic defense budgets are "supporting the troops."