“This week’s brief takeover of the Iraqi parliament in Baghdad’s heavily guarded Green Zone may have been political theater, but it was part of a real-life drama that’s deadly serious and may or may not have a happy ending for Sunnis, Shia, Kurds — or the United States. American casualties will likely rise in the fight against ISIS — and in support of a government too weak to hold the country together. We look at the struggle to prevent a bad situation from growing worse.”