Coercion as a Ground Affecting the Validity of Peace Treaties

The rule enshrined in Article 52 of the Vienna Convention is not a mere statement of principle: international practice confirms that it reflects a customary rule which, however, does not play a significant role as regards coerced peace treaties. Cases such as those concerning the Lusaka Ceasefire Agreement between Congo and Uganda or the Military and Technical Agreement between Serbia and KFOR show that victims of coercion tend to waive their claim as to the validity of peace treaties, since they have a strong interest in their implementation. The possibility of such a waiver is discussed in the light of Article 45 of the Vienna Convention and of the peremptory nature of the prohibition of the use of force.