From [HERE] The US government on Tuesday insisted in a letter to the UN that the American-led airstrikes in Syria against the Islamic State (IS) were legally justified because actions were taken in defense of Iraq. The US, with the support of Bahrain, Jordan, Saudi Arabia, the United Arab Emirates and Qatar, led the airstrikes without first seeking permission from the UN Security Council [official website] or the Syrian government. However, the US argued that under Article 51 of the UN Charter, [text] countries have the right to defend themselves with the use of force. International law dictates that force on another sovereign country may be used without the permission of the country's government or the UN in matters of self-defense. The airstrikes were legal, the letter stated, because Iraq asked the US for help in defending itself against IS attacks. Additionally, the Khorasan, [BBC backgrounder] who were also targeted in the attacks, were deemed by American intelligence to be a threat to the US. In her letter to UN Secretary-General Ban Ki-moon, Ambassador Samantha Power [official profiles] urged that "States must be able to defend themselves ... when, as is the case here, the government of the state where the threat is located is unwilling or unable to prevent the use of its territory for such attacks." [MORE]