●Sending more Apache gunships to Iraq to counter the extremists’ offensive in Anbar province. Some of these deadly attack helicopters are already at Baghdad’s airport, and more could be sent to al-Asad Air Base in western Anbar, which remains under government control. From these two bases, a squadron of 20 or so Apaches could attack the Islamic State’s enclaves from al-Qaim in the northwest to Abu Ghraib in the Baghdad suburbs. Dempsey pointed to the Apaches last weekend in a TV interview as an “immediately available” tool to defend the Baghdad airport.

●Stepping up airstrikes over Iraq and Syria. Some officials argue that, to stop the extremists’ advance, 150 to 200 sorties a day may be needed, a sharp increase from 10 a day recently. Air power has limited effect against this insurgency, but Pentagon and State Department officials say right now it may be the only way to prevent further losses.

●Accelerate the training of the Iraqi army and a new Sunni national guard.