WASHINGTON (AP) — The U.S. decision to strike the Khorasan Group to stop a possible terror attack represents a significant expansion of the largely secret war against core al-Qaida, a group President Barack Obama has proclaimed was “a shadow of its former self.”

Administration officials said Tuesday they have been watching the Khorasan Group, an al-Qaida cell in Syria, for years. But Obama had resisted taking military action in Syria to avoid inadvertently helping President Bashar Assad, a leader the U.S. would like to see gone. That changed, officials said, because intelligence showed that the Khorasan Group was in the final stages of plotting attacks against the U.S. and Europe, most likely an attempt to blow up an airplane in flight.