Delegations raise relations only up to a point; beyond that they are fed by TREATIES (friendship, defense pact, military alliance). Free trade removes tariffs, and free borders open migration.
WAR: the war score (−100..100) shifts each day with the balance of power, and monthly battles inflict heavy losses. With enough score you DICTATE the peace (reparations, factories, population, resources, disarmament, PUPPET).
PUPPET: you turn the loser into a puppet — you run its foreign affairs and its income flows to you. A puppet wants independence, and a wide network of influence stays restless (balance of power).
Aggressors become isolated, common enemies unite (coalition). Your ally can call you into war.