People always have something to lose, and war rarely makes sense at first glance...just look at World War 2. Did Germany benefit from getting reduced to rubble and ultimately partitioned into 2 states? No, of course not, but it still happened. Errors in judgement happen, miscalculations happen...lets take a more recent war, the Vietnam War. It was based pretty much 100% on total bullshit and a profound misreading of the political situation in southeast Asia, people like Robert MacNamara have admitted that much...yet it drug on and on and resulted in the deaths of millions.
I don't necessarily believe that the next world war is "right around the corner", nor do I discount the element of media hysteria...hell, it's probably mostly that, and there's been a noticeable shift lately away from Russia fear-mongering and towards China fear-mongering...China's ambitions as an "expansionist power" are routinely hyped up by propagandists here in the USA...but at the same time the idea of "they have something to lose from it just like we do", while correct on the face of it, doesn't really do it for me as far as reassurance goes. We're the exact same people we were in the early 20th century...a century is just the blink of an eye really, as far as how long we've been around, with all the same kinds of prejudices, flaws, rivalries, political systems etc. only now we also have thermonuclear weapons. As people like Einstein and Oppenheimer pointed out when the first atomic bomb was created, a technological leap like that which isn't accompanied by a corresponding biological leap in human consciousness probably bodes ill for us over a long enough time frame...but maybe (I hope!) I'm wrong...we've certainly had some close calls in the past