Let's say WWI comes to happen like OTL, except instead of dragging on for four years, it ends relatively early. Say France falls in 1914, and then Russia Sue's for peace either that same year or the next. Obviously the war wouldn't have been as bloody as OTL, but does this actually solve any of Europe's problems? Will the tide of socialist revolution be dampened, along with the inevitable reactionary response? Would the national rivalries that consumed the continent for centuries recede? Or is violent, chaotic change still inevitable?
Shucks, ANYONE winning quick would probably have been better. The damage WW1 inflicted is beyond imagining.
France almost certainly settles down to being a second-rank power in Germany's shadow, much as Austria-Hungary had since 1866. Violent Socialist uprisings aren't on the cards unless the war lasts into 1916 (which is shorter, but not what I'd call "quick"). Multiethnic empires as a concept aren't discredited. Austria-Hungary, having put in a poor showing in the war, will likely be forced to take major internal reforms, but it's pretty unlikely that it breaks up. If France falls in 1914, Italy is highly unlikely to join the war, so avoids many of the reasons for it's political woes in the interwar years.
Britain won't be happy, and could be the one to start the next war. I really wonder what would happen to Ireland too? On the other hand, Germany emerging as such a power in Europe combined with Britain not suffering much direct damage could well mean beneficial reforms to the empire.
Not sure what would happen to the Ottomans here, odds are Germany will be trying to make them a de facto colony, and once Russia recovers, an Ottoman-Russian war is a risk. On the other hand, the Ottomans have a real chance to develop some real strength again, and the Ottomans and the other powers in Europe will be throwing spanners at Germany and Russia.
China would be different, without the hope and disappointment of OTL's WW1. Not sure exactly how things would go there though. Japan and Spain (as well as Latin America) wouldn't experience such explosive growth fueled by war production, but they don't suffer the post-war crashes either.
Probably that's a good thing on balance, leading to more political stability. World trade-patterns aren't so badly disrupted.
It would be a much less democratic world though. Without the old system being so thoroughly discredited, things will change more slowly.
fasquardon