Worldbuilding without the post-WW/WWII/Cold War glasses (TL, CR etc.)

[Lord Carnifex]

Without the world wars, there's probably no concept of "total war" that involves attempting to destroy the enemy's industrial, transportation, and agricultural base as a means of impairing their abilty to continue making war. Without that basic idea, war becomes more about capturing such things rather than wiping them off the map.

Without total war, there's less targeting of civilians and civilian infrastructure. War stays slightly less horrific and WMD's are less common and more tactical. As such, there's less popular support for peace and disarmament movements (which probably more closely resemble the isolationist movements of the pre-WWI and II U.S.). And so, many fewer hippies.

Without total war, there might be less of a drive for unconditional complete surrender of the enemy nation, particularily for ideological motives. Once you've taken whatever territory you've set out to take (or repelled the invaders), you make peace with the enemy nation. Keeping the war going until you defeat them completely, and then remaking their internal politics probably happens less often. So less nation building and resources spent on nation building.

Probably without the World Wars and Cold War, there might be less of a bilateral world. Two nations may go to war without dragging in all of the other major players, and times of relative peace without a complete, bi-polar, us-against-them "pick a side" attitude may be possible and occur more often.