The United Nations was founded after World War II to promote global security. But following the bitter divisions created in the Security Council last year by the U.S.-led Iraq war, some observers question whether the U.N. can foster global peace and stability. Critics contend that Article 51 of the U.N. charter, which grants nations the right to self-defense, doesn't allow them to act against rogue states and terrorists. Others say the Security Council lacks credibility because many of today's big powers — like Japan and India — are not permanent members. But U.N. supporters say the charter does allow nations to counter threats, even pre-emptively, and that the Security Council can effectively promote peace and security.