The Sunni militant extremists who have seized a broad area of Iraq extended their control on Monday to the country’s entire western frontier, having secured nearly all official border crossings with Syria and the only one with Jordan, giving them the semblance of the new independent state that they say they intend to create in the region. With the seizure of the Jordan crossing, which militants from the Islamic State in Iraq and Syria first assaulted late Sunday night, the Iraqi military defenses crumpled, as they have in other battlegrounds in the western and northern parts of the country over the past two weeks. ISIS control of the Jordan border raised the risks that its insurgency could menace not just Syria and Iraq, but Jordan and Saudi Arabia, two important American allies. The border seizure came as Secretary of State John Kerry made an emergency visit […]