Question

preventing the outbreak of a new war is the purpose of the
un secretariat.
un security council.
un peacekeeping forces.
international court of justice.

Explanation:

The UN Security Council's main role is to maintain international peace and security, which includes preventing new wars. The UN Secretariat handles administrative tasks. UN peacekeeping forces are deployed after conflicts start (though they can help prevent escalation in some cases but their main role is post - conflict or during ongoing conflicts). The International Court of Justice deals with legal disputes between states.

Answer:

UN Security Council.