I swear, there has to be something in alternate history, maybe something that unlocks a secret compartment in your mind, because my god, some of the most left-leaning, anti-imperialist, generally anti-war folks I know suddenly turn into belligerent nationalists blowing the trumpets of war.
Suddenly, people are talking about setting up puppet states and exploiting the hell out of them with no sense of irony or self-awareness.
Do you mean writing about big wars & imperial, or going "YEAH!" about it in AH? The former shouldn't be too surprising, a story about war breaking out is more immediately exciting than one where the war doesn't happen and the tanks all go home