Did the UN request the United States' istance in Libya or did Obama decide?

The group of middle eastern countries requested to the UN that they take action. After ping the resolution (which the US voted for it), the UN asked the countries with large military powers to intervene and the countries have an obligation to respond. What you are probably digging for is that Obama was urging the middle eastern countries to get together and request the action. France was the country that did most of the bombing. Why? France was the country that sold Libya most of their weapons. z