All U.N. members must comply with Security Council decisions, and the Council sends peace-keeping forces to restore order when needed. The Council can impose economic sanctions or an arms embargo to pressure countries that don't comply, and it authorizes the U.N.'s members to take military action if needed.

What is the United Nations and how does it work?

The United Nations is an international organization founded in 1945 and committed to maintaining international peace and security; developing friendly relations among nations; promoting social progress, better living standards and human rights.

Does the UN actually do anything?

The United Nations has saved millions of lives and boosted health and education across the world. But it is bloated, undemocratic – and very expensive. ... The UN's children's organisation, Unicef, provided an education and a path to a better life for millions, including the present UN secretary general, Ban Ki-moon.