For President Obama, an endorsement of signature strikes would mean a significant, and potentially risky, policy shift. The administration has placed tight limits on drone operations in Yemen to avoid being drawn into an often murky regional conflict and risk turning militants with local agendas into al-Qaeda recruits.

“How discriminating can they be?” asked a senior U.S. official familiar with the proposal. Al-Qaeda’s affiliate in Yemen “is joined at the hip” with a local insurgency whose main goal is to oust the country’s government, the official said. “I think there is the potential that we would be perceived as taking sides in a civil war.”