The effect of war upon existing bilateral treaties of belligerents is one of the unsettled problems of international law. The problem is to determine whether a bilateral treaty (between nations at peace) which does not provide for the eventuality of war, will be suspended or annulled by a subsequent war between them. The idea that war is a complete destruction of the international intercourse which was represented by the treaty logically would lead to the conclusion that the treaty ends ipso facto when war comes. But this is too hasty a conclusion; international practice proves that some treaties are only suspended, some abrogated, while others remain in force.
J. G. Castel,
INTERNATIONAL LAW-EFFECT OF WAR ON BILATERAL TREATIES-COMPARATIVE STUDY,
Mich. L. Rev.
Available at: https://repository.law.umich.edu/mlr/vol51/iss4/6