tl;dr: Here's a crazy notion I've had for several years, wondering what you all think: I think there should be spoils in war like in ancient times. Nations that win a war should take over the defeated nation, if they want it.
Premise: War is bad, and is to be avoided at all costs. A nation should only go to war if its very existence or security is directly threatened (or an ally's). You don't go to war to meddle in other another country's affairs or make them do what you want. But if you do have to go to war, under "honorable" conditions such as being attacked first, then if you win you take whatever you want from the defeated nation, and if they or anyone else bitches about it, too bad.
Background: Whatever happened to the spoils of war and conquest? As I understand ancient history, when one nation or empire went to war with another and defeated them, they took the liberty of collecting whatever spoils they wanted from their defeated enemy. They took the land, possessions, and even people. This was ugly, and in many cases included atrocities like rape and genocide. I'm definitely not advocating those things. Their empire expanded (sometimes to their own ruin), but the point is they felt free to take whatever they damned well pleased, because they had vanquished their opponent.
I suggest that the prospect of such ruin made nations think carefully before they engaged in a war, especially against a powerful opponent (although WWI, a fairly modern and stupid war, might belie this idea). Anyway, many nations found other ways to try to resolve their differences (such as sending emissaries and tithes) and sought allies to avoid being conquered by other powerful nations.
Eventually a bunch of countries got together and formed some conventions outlawing taking spoils and conquest. But is that a good thing? I suggest that in modern times, if a country is audacious enough to go to war, then collecting spoils and outright conquering should be okay. Instead, after a modern war and blowing everything up, the winning country typically spends more money helping the defeated country to rebuild itself, and attempts to install a new, more palatable government, with highly dubious results.
So here's an example: Back when the U.S. invaded Iraq in 2003 (a very poor decision, IMO), we sent young men and women into harm's way to do battle there. Lots were killed, many more were grievously injured. We killed probably 100,000+ Iraqis. The U.S. spent trillions of dollars fighting that war. Accusations were made by some that it really was a "blood for oil" war, that the U.S. was really just interested in taking or securing Iraq's oil reserves. At one point, the Bush/Cheney administration even promised that the U.S. would finance the war with Iraqi oil, but that never materialized as far as I know.
At the time, I thought the decision to invade was stupid (and I still do). But, I thought, if our country thinks it is so damn important to invade Iraq because of national security concerns, then we literally should turn it into the 51st U.S. State when we win. If you're going to risk lives and everything else going to war, then take over the whole thing, especially the oil fields. Unless, that is, we determine it would be more of a headache trying to hold it, in which case you'd just leave it, destroyed, and definitely not spend one cent rebuilding it. So, we would now have the State of Iraq, just like the State of New York or Hawaii with all the inherent rights and privileges under the U.S Constitution. The people there would be free to do whatever they want under U.S. laws, including practicing whatever religion they please. If the U.S. Government is not comfortable attempting to establish the U.S. State of Iraq, then you better think twice before going to war because otherwise it's probably not worth it.
Modern warfare seems almost too sanitary, in the sense that no really bad, long-term consequences hit the offending parties. They're just rebuilt, and it's a crap shoot how the new regime will turn out (see: today's Iraq). I think bona fide conquering would help avoid unnecessary wars.
What do you think? It seems perverse with our "modern sensibilities", but I honestly don't see the downside (besides the obvious one of the people not wanting to come under a new nation -- but oh well, is the alternative any better?)!