break_tributary_contract_due_to_attack_effect

break_tributary_contract_due_to_attack_effect = {
	save_scope_as = attacker
	if = {
		limit = { is_tributary_of = $DEFENDER$ }
		reverse_add_opinion = {
			modifier = tributary_ceased_payments_opinion
			target = $DEFENDER$
		}
		$DEFENDER$ = {
			send_interface_toast = {
				type = msg_tributary_contract_broken_due_to_war
				left_icon = $DEFENDER$
				right_icon = scope:attacker
			}
		}
		send_interface_toast = {
			type = msg_tributary_contract_broken_due_to_war
			left_icon = scope:attacker
			right_icon = $DEFENDER$
		}
		end_tributary = yes
	}
	else = {
		if = {
			limit = {
				scope:attacker = {
					NOT = { has_character_flag = allowed_war_declaration_sans_truce_penalties }
				}
			}
			reverse_add_opinion = {
				modifier = betrayal_opinion
				target = $DEFENDER$
				opinion = -50
			}
		}
		send_interface_toast = {
			type = msg_tributary_contract_broken_due_to_war
			left_icon = scope:attacker
			right_icon = $DEFENDER$
		}
		$DEFENDER$ = {
			send_interface_toast = {
				type = msg_tributary_contract_broken_due_to_war
				left_icon = $DEFENDER$
				right_icon = scope:attacker
			}
			end_tributary = yes
		}
	}
}

As written in game/common/scripted_effects/00_war_effects.txt.