Game concept · The Fate of Iberia
Enforce Truce
The game also links it as Enforced Truce.
From the game's encyclopedia
This is a special type of Interaction available to Involved Rulers which ends a War in a White Peace and establishes Truces.
It may only be used to end wars between other Involved Rulers of lower Rank in which at least one side is Independent or part of the same Realm.
The game's text for patch 1.20.1.2. Words in blue are entries of the encyclopedia: hover one to read it, as in the game.
Enforce Truce is an entry of Crusader Kings III's in-game encyclopedia (The Fate of Iberia). The game explains it: "This is a special type of Interaction available to Involved Rulers which ends a War in a White Peace and establishes Truces." The game also links it as Enforced Truce. Patch 1.20.1.2, from game/common/game_concepts/03_fp2_game_concepts.txt and game/localization/english/game_concepts_l_english.yml.
Source: game/common/game_concepts/03_fp2_game_concepts.txt, game/localization/english/game_concepts_l_english.yml and the English localisation, Crusader Kings III 1.20.1.2.