Article 96: Declaration of war

Article 96
  1. A declaration that the Kingdom is in a state of war shall not be made without the prior approval of the States General.
  2. Such approval shall not be required in cases where consultation with Parliament proves to be impossible as a consequence of the actual existence of a state of war.
  3. The two Houses of the States General shall consider and decide upon the matter in joint session.
  4. The provisions of the first and third paragraphs shall apply mutatis mutandis to a declaration that a state of war has ceased.

Explanation

Please note: Only the Dutch-language version of the Constitution has legal effect. 

The Government may not declare the Kingdom to be in a state of war without the prior approval of the States General.
Proceedings in a joint session are prescribed to prevent one House from voting in favor of the declaration of war while the other does not.

International law prohibits wars of aggression. The UN Charter permits individual or collective self-defence subject to its conditions. The UN Security Council may also authorise the use of armed force under Chapter VII of the Charter.

The consent of the States General is not required when consultation with the States General is not possible due to a war already underway. The requirement of prior consent from the joint session also applies to the declaration that a war has ended.