Logistics is effectively the hardest problem and the most expensive one.

A lot of people don't realize that a lot of wasteful spending is effectively required in order to maintain any semblance or level of readiness.

If you are not manufacturing equipment, ammunition, and similar items then you have no one and nowhere to actually manufacture them. A large part of spending is keeping the people, skill sets, facilities, and supply chains running and operating at a minimum required level to support an increase in need. If you don't do this then when you need it, you can't manufacture it anymore, your entire supply chain has to start from scratch.

It's incredibly wasteful but also somewhat necessary.

Like 90% of the military is just good logistics and the ability to move resources anywhere in the world quickly.

There’s an old WW2 story, where a captured Nazi officer realized they were going to lose the war… Because he overheard American officers complaining that they were running low on ice cream. Nazis at the time were eating their own boot leather while they froze to death in Russia. Meanwhile, the Americans were complaining about a lack of ice cream.

The logistics behind the American military is honestly a modern wonder. If they were willing to divert the time, manpower, and resources to do so, they could erect a fully staffed and stocked McDonalds anywhere on the globe in less than 48 hours. Imagine an entire restaurant being built in a single weekend. Now imagine it in the middle of the ocean on an oil rig, or at the North Pole. The sheer amount of resources and manpower required would be monumental by most standards, but it wouldn’t even be worth a footnote on the military’s expense report.