Two months ago we laid out a plan on these pages to bring Iraq back from the abyss of terrorist domination, turn the tide in the Syria conflict, and crush the advance of the Islamic State of Iraq and al-Sham. The need for such a plan is now more urgent as ISIS has since advanced dramatically, the Iraqi army and Kurdish militia initially performed poorly, and the terror group has threatened to kill more Americans as it did James Foley last week.

President Obama has so far ordered some 1,100 troops into Iraq and conducted close...