This is the saddest part of it. Wars have economic benefit because of the giant injection of spending and incentives for investment. One could have the same benefit using much less destructive and even beneficial projects such as colonizing the oceans or space or building gigantic solar power plants to solve all our energy problems.
Alas, there seems to be always at least one party that is opposed to any kind of visionary project.
Yes, possibly literally. Major wars are often the ultimate solution to this kind of problem. When the dust settles a new order exists.
I detest war. I detest human suffering. But it appears sometimes war has amazing cleansing power. Hopefully this isn't always the case.