And even if it was he's still wrong. Land itself has value, and with sufficient brutality you can still "win". The fact that we haven't seen a war like that since 1945 in the developed world doesn't mean it's not going to happen again. Hitler planned to basically kill everyone to the east of Germany and replace them with Germans. That would have been "winning" by any definition of the word.
If he meant only that war currently has no financial value, I don't see why he'd make references to Assyria or Rome. Because whatever value those peoples derived from conflict wasn't most likely in increased treasuries, but instead in the extension of land and in the number of subjects, which in itself can be very valuable things to warlike societies as it improves their ability to wage war, either by increasing the defensibility and depth of their borders or by making them able sustain larger armies.
I've might have read him more generally than he meant, though. But still, I don't see the need for such a specific reading.
I find that construction odd. Are you trying to say all goals of war are ultimately economic? If so I think that's needlessly restrictive.
>Because whatever value those peoples derived from conflict wasn't most likely in increased treasuries, but instead in the extension of land and in the number of subjects...
I know next to nothing about Assyria, but the Roman treasury profited quite handsomely from conquest, to the point that in the Republic's most expansive period you only had to work two days a year as a Roman citizen to pay your taxes.
Because when the Romans conquered a people they took everything that wasn't nailed down, sold the land, sold the rights to collect taxes in that area, and then sold people themselves.
We also shouldn't discount that the world today has so much more globalization. Just about every country has become interdependent on each other.
There are credible arguments that the Second Red Scare (which started after WWII) was the result of ruling classes in capitalist countries becoming afraid that they would be the victims of a proletariat revolution. A revolution like Cuba's would have been their worst nightmare.
That's perhaps not a cold economic calculation, but almost certainly an economic one.
There are also many Middle Eastern conflicts that the US is only involved in because we're afraid of losing access to oil.
I don't think many hunter gatherers died of traffic accidents or obesity.
About the Roman bit, the real issue would be how much of any direct monetary gain from conquest ended up in the hands of the Roman state rather than in the hands of private citizens.