On 19 March 2011, a coalition of United Nations member states led by France, the United Kingdom, and the United States began military operations in Libyan airspace and territorial waters after the United Nations Security Council approved UNSCR 1973, ostensibly to prevent further attacks on civilians as loyalist forces closed in on Benghazi, the rebel headquarters. In response, Gaddafi declared that a state of "war with no limits" existed between Libya and the members of the coalition. Despite this, he sent a three-page letter to US President Barack Obama imploring him to "annul a wrong and mistaken action" and stop striking Libyan targets, repeatedly referring to him as "our son" and blaming the uprising on the terrorist group al Qaeda.