Rule 4

The fundamental principle is that, in any armed conflict, the right of the Belligerent Parties to choose methods or means of warfare is not unlimited.

[Commentary]

  1. This basic Rule is based on Art. 22 of the 1907 Hague Regulations[130] and on Art. 35 (1) of AP/I.[131] All the Rules in this Manual lead back to this fundamental principle.
  2. The main direct consequence of Rule 4 is the fundamental principle that military necessity does not justify any exception from any Rule in the Manual, unless such an exception is expressly stated in the Rule (see, e.g., Rule 95 (b)).
  3. There is no difference in this respect between international and non-international armed conflict.
    1. Art. 22 of the 1907 Hague Regulations: “The right of belligerents to adopt means of injuring the enemy is not unlimited.” Wording identical in the 1899 Hague Regulations.
    2. Art. 35 (1) of AP/I: “In any armed conflict, the right of the Parties to the conflict to choose methods or means of warfare is not unlimited.”