PoliticsU.N. Secretary-General: Use Of Force Lawful Only If Security Council Approves"That is a firm principle of the United Nations."By by Jacob FischlerBuzzFeed News ReporterPosted on September 3, 2013, 6:11 pmTwitterFacebookLink United Nations Secretary-General Ban Ki-moon: "Use of force is lawful only when in exercise of self-defense in accordance with Article 51 of the United Nations charter and or when the Security Council approves such action."