I'll hope someone knows, so that I can reevaluate my knowledge.
I've looked around more on this, and DanF5771 offered some info on this topic long ago.
https://forums.civfanatics.com/thre...-getting-out-of-wheoohrn.325581/#post-8208698
^That was indeed just happening by coincidence as the mechanics for exiting WHEOOHRN are totally independent of changes in the target's power --> you can delete ALL of your units and they still might switch out of WHEOOHRN!
To my knowledge there are only 2 situations that make AIs drop their war preparations:
Peace treaties as a result of one-sided trades (give help, accept demands) will only postpone war.
- They are preparing for a total war against a land target and lack the necessary offensive units; this judgement solely depends on the number (not strength) and UnitAI of their units in relation to the number and size of their cities (Saladin in ALC#24).
- They get DoW'd on by someone else before they start their planned war.
Possibilities are rather limited:
- Gift them happy and health resources so that they can grow fatter with larger cities (success is rather uncertain), or even gift them a city
. Also there is the risk (and no way to tell for sure) that they might have skipped the revocable preparation phase (WARPLAN_PREPARING_TOTAL) due to using Dagger strategy (immediate WARPLAN_TOTAL).
- Bribe other players into a war against them.