Assuming Russia still goes Bolshie (and quite possibly sooner), the Red would have a heyday in the 3rd World and no liberal democracy to counter their appeal to popular revolt. Africa, the Balkans, the crumbling Ottoman Empire, and India-partitioning would turn into bloodbaths. The one good thing that the two World Wars did was take the piss out of ideology driven government. Pragmatism and gung-hoism won the day both times (and again in the Cold War).
I can see the US being much more libertarian, smitten with screw-you economics without the Greatest Gen being sustained by the collectivism brought on by the wars. Progressivism was burning out in the 1910s. Any kind of New Deal experiments wouldn't have lasted as long or ever engendered Republican support like they did in the mid-century. Eventually that populist appeal of rugged individualism is gonna win the American consensus without the influence of great global conflicts pulling millionaires and labor leaders together.
Meanwhile the successor to the German & Austrian Empires would become more nanny statish in order to placate their restless lefties. As many faux-democratic autocrats are demonstrating in OTL's current trends, a skillful blending of soft authoritarianism coupled with a strong social welfare state is a powerful recipe for stable government. The more crowded the big nations become, the less liberal, permissive democracies are going to work as global powers. Formerly liberal regimes in the US, Turkey, Brazil, and across Eastern Europe find that a hint of Big Brotherism goes a long way toward holding power in multinational states.
Britain might plod a separate path, perhaps still trying to liberalize its colonies into a Commonwealth, but that will leave the Common/Empire really vulnerable to being pulled into regional conflicts as the more imperially oriented European powers (Germany, Italy, Austria, Netherlands, Spain, Portugal, & Belgium) move to suppress their colonial uprisings (and the colonized insurgencies form global alliances, for which the Bolsheviks would provide global support.
There would still be a few big wars. Britain and Turkey would inevitably fight over the MidEast. Soviet Russia would want to expand into the Balkans, the Black Sea, and south of the Caucuses. Japan would still want to grab the Philippines and wrest more territory from China. Independent kingdoms like Iran and Siam would try to follow Japan into industrialization and become puppets for the Europeans and Japanese to try and win over, leading to border clashes and probably proxy wars among the Europeans. Germany would want to dominate the Baltic states if they managed to get free of the Bolshevik state.
Lots of fodder for thought in the global possibilities here.