system
Given the following post, respond as if you're commenting on Reddit:
human
[Discworld] How did (alternate) Ankh-Morpork lose the war so quickly?

Partway through _Jingo_, Vimes grabs a dis-Organizer belonging to a version from him from a different pants leg of time, one where he didn't go to Klatch to stop the war from happening. As a result, we're treated to a terrifying view into what would happen - Klatch invading Ankh-Morpork and killing him and everybody...

Except... at the time he gets that view of the alternate present, the two armies are only about to clash... in Klatch. There's little doubt the A-M army is about to be soundly trounced, but it's still a long while before the Klatchians can cross the sea the other way and get their murder on.

So... if Vimes' decision is the only thing that differs between the pants legs, how did it prevent the invasion happening so soon?
gpt
Klatch Army and Navy is probably prepared and just around the corner. Its the actions of men like Vimes and Ahmed that prevented a massacre of An-Mo...and in a few years down the road, complete conquest of Klatch by AM merchants from within.

Klatch was ready to annihilate Ankhmorporkian military, but was woefully unprepared for being ankhmorporked from within. Ankh-Morpork is not a city, it is a *state of mind* a viral tumour of urban cynicism that would subvert them. 

It was in the interests of both nations NOT to fight, but both were 100% prepared to win.