The United States told the United Nations on Tuesday it led airstrikes against Islamic State militants in Syria because President Bashar al-Assad's government had failed to wipe out safe havens used by the group to launch attacks on Iraq.
In a letter to U.N. Secretary-General Ban Ki-moon, U.S. Ambassador to the United Nations Samantha Power wrote: "The Syrian regime has shown that it cannot and will not confront these safe havens effectively itself."
The strikes were needed to eliminate a threat to Iraq, the United States and its allies, she wrote, citing Article 51 of the U.N. Charter, which covers an individual or collective right to self-defense against armed attack.