The news out of Iraq just keeps getting worse. Now Turkey is threatening to send troops across the border to wipe out Kurdish rebel bases, after guerrillas killed at least a dozen

Turkish soldiers. But it is one more widely predicted problem the Bush administration failed to plan for before its misguided invasion — and one more problem it urgently needs to deal with as part of a swift exit from Iraq.

Washington should explain the dangerous facts of life to the leaders of Iraqi Kurdistan, who have done nothing to rein in the guerrillas or drive them out of their territory. Iraq’s president, Jalal Talabani, who is a Kurd, did no good when he said he wanted “to solve problems peacefully,” but then declared that Iraq would not even turn over “a Kurdish cat” to Turkey.

Washington must now try to walk both sides back from this brink. It then should make a serious and sustained effort to broker a long-overdue political agreement between Turkey and Iraqi Kurdistan. Iraqi Kurds want access routes to sell goods to Europe. Turkey needs a secure border with Iraq. With so many other problems in Iraq, the Bush administration

apparently thought it could ignore this one. It can’t. If it doesn’t now move quickly, Iraq’s disastrous civil war could spiral into an even bigger disaster — a regional war. —