President Barack Obama acknowledged that U.S. intelligence agencies underestimated the threat from Islamic State militants in the Middle East and overestimated the ability and will of Iraq’s army to fight such extremists.

President Obama described the U.S. intelligence assessments in response to a question during a CBS “60 Minutes” interview that aired Sunday. Obama said he had no choice but to order U.S. air strikes on Assad’s enemies, the Islamic State and the Khorasan Group because “those folks could kill Americans.”

He noted that his director of national intelligence, James Clapper, has acknowledged that the U.S. “underestimated what had been taking place in Syria.” Obama also said it was “absolutely true” that the U.S. overestimated the ability and will of the Iraqi army.

The Islamic State group, which derived from but has broken with al-Qaida, has taken control of large sections of Iraq and Syria. The Khorasan Group is a cell of militants that the U.S. says is plotting attacks against the West in cooperation with the Nusra front, Syria’s al-Qaida affiliate.

Sen. John McCain, who lost the presidential election to Obama in 2008 and has been a frequent critic on foreign policy, said Monday that the administration had miscalculated the necessity for the United States to keep a residual force of troops in Iraq after the war there ended.

“We predicted exactly what would happen. … It’s like watching a train wreck. A residual force would have stabilized the situation. It is a direct result of our failure to leave a residual force there.” -U.S. Sen. John McCain, R-Ariz.

Obama said his first priority now is degrading the extremists who are threatening Iraq and the West. To defeat them, he acknowledged, would require a competent local ground force, something no analyst predicts will surface any time soon in Syria, despite U.S. plans to arm and train “moderate” rebels.

Obama made clear he has no interest in a major U.S. ground presence beyond the 1,600 American advisers and special operations troops he already has ordered to Iraq.

“We are assisting Iraq in a very real battle that’s taking place on their soil, with their troops. This is not America against ISIL. This is America leading the international community to assist a country with whom we have a security partnership.” – U.S. President Barack Obama

White House spokesman Josh Earnest said Monday the president was not seeking to pin blame on the intelligence community and said the commander in chief “is the one that is ultimately responsible for protecting the national security interests of the United States of America.”

This story was compiled with information from the Associated Press.

CCTV America’s Elaine Reyes interviewed Georgetown University Professor Anthony Clark Arend.