The UN Security Council (UNSC) was established at the founding of the UN, in 1945, and first met in 1946. The Security Council is arguably the most powerful organ within the UN, as it is the only body that can pass binding resolutions, including the power to approve military action and sanctions.
It is comprised of fifteen states, five of which are permanent—the United States, Russia (originally, the USSR), China, Britain, and France—and can exercise a veto on any potential resolution.