- Countermeasures — Conduct of hostilities — State practice — Unilateral acts — Reprisals
Published under the auspices of the Max Planck Foundation for International Peace and the Rule of Law under the direction of Rüdiger Wolfrum.
1 The term ‘ultimatum’ was originally used in diplomacy as a method to enforce a certain demand by the threat of force. The common legal understanding, which has come about with State practice in the 19th century, conceives an ultimatum as a unilateral declaration by a State or a group of States which directs a peremptory warning against another State that certain consequences will follow unless defined conditions are met (Unilateral Acts of States in International Law). Usually, but not necessarily, a certain period of time, short as it may be, is fixed for...