This screenshot shows the tooltip text for the 'pacify' and 'punish' decisions:https://photos.app.goo.gl/cyhfuNtvo6xAwzir5
There is no mention of any probability of success - unlike other decisions which do have a chance of failure over multiple turns.
Looking at the tooltip text more closely but, I wonder if there is some inconsistency with the green province highlight that shows on the map where the decision is valid. I'm certain I got that green highlight on provinces without any city, for example! Indeed that was the whole aim - to disrupt supply by blocking a ribbon of provinces.
In fact, see the next screenshot. 'Punish' selected with several provinces without cities showing as valid!https://photos.app.goo.gl/4jf57VF2kyjPkqmg8