Preventing a Slaughter in Iraq

The catastrophe of Iraq has been growing steadily worse for weeks, but by Thursday, it became impossible for the United States and other civilized nations to ignore it. Iraq’s bloodthirsty Sunni extremists were threatening the extermination of tens of thousands of members of religious minorities who have refused to join the fundamentalist Islamic state the terrorist forces want to create.

The Islamic State in Iraq and Syria, known as ISIS, drove Christians, Yazidis and other minorities from their homes by giving them a choice between religious conversion or slaughter. There have been reports of scores of civilians being killed. Many of these frightened and desperate people have surged toward the Turkish border and some 40,000 are estimated to be suffering from heat and thirst on Mount Sinjar in northeast Iraq.

So it was not surprising to hear President Obama announce Thursday night that the United States was dropping food and water supplies in northeast Iraq and that he had authorized targeted airstrikes against ISIS, if needed. Mr. Obama made a wise policy call, and showed proper caution, by keeping his commitment not to reintroduce American ground troops in Iraq, but humanitarian assistance for the imperiled civilians was necessary.

Turkey’s foreign minister, Ahmet Davutoglu, said his government had begun providing aid to these Iraqis, including dropping supplies at Sinjar from Iraqi helicopters. Turkey, already inundated with refugees from the Syrian civil war, is building a refugee camp in northern Iraq. An American official told The Times that fear of a “humanitarian catastrophe” had prompted Mr. Obama to consider the airdrops of emergency supplies and airstrikes against militants besieging the mountain.

From a political viewpoint, Mr. Obama created credibility problems for himself last year when he raised the strong possibility of military retaliation against Syria for using chemical weapons in the civil war there, then reneged in favor of a diplomatic deal with Russia that forced Syria to give up its stocks of chemical weapons. He ran the danger of compounding that problem if he did not act now.

Mr. Obama shaped the issue in terms of a humanitarian crisis — he said ISIS had talked of the destruction of the Yazidis, an ancient sect, and said that would be genocide. He voiced alarm over the rapid gains of ISIS, a brutal former affiliate of Al Qaeda that aims to establish a caliphate across Syria and Iraq that would be governed by a harsh interpretation of Islamic law, and he showed determination to protect American diplomats and other personnel at the consulate in Erbil and at the embassy in Baghdad.

The militant forces, battle-hardened, flush with money and weapons, have racked up stunning victories against the well-trained and highly motivated Kurdish pesh merga forces. They were reported to be controlling a checkpoint at the border of the semiautonomous Kurdish region, which is only 30 miles from the government headquarters in Erbil. ISIS also appeared to have captured the Mosul dam, the largest in Iraq, which provides electricity for Mosul and controls the water supply for a large territory. Should that structure fail, or be damaged in the conflict, it could flood with catastrophic consequences.

Iraqi Kurds were vital allies in the American-led war that toppled Saddam Hussein and continue to have close ties to the American government. Their semiautonomous region — peaceful, prosperous, reasonably well governed and an oil producer — has been the consistent bright spot in Iraq’s tumultuous postinvasion history. It would be a huge blow for the Kurds, Iraq and Turkey, a NATO ally, if ISIS took over the region.

Speaking at the White House, President Obama again pressed Iraqi politicians to resolve their differences. A move by Iraq’s government to appoint a prime minister who could credibly unify the country and lead the counterattack against the extremists has stalled. That division, Mr. Obama said, plays into the terrorists’ hands.

After so many years in Iraq, Americans are justifiably skeptical about what military involvement can accomplish anywhere — and the Middle East is so complicated that even seemingly benign decisions can have unintended consequences.

The United States, Turkey and other allies should move quickly to meet the Kurds’ needs for ammunition and weapons as well as advice on more effectively deploying the pesh merga and integrating Kurdish operations with Iraqi security forces. Under pressure from the United States, Prime Minister Nuri Kamal al-Maliki of Iraq finally agreed this week to cooperate with the Kurds and to provide air support, and should continue to do so. That will still leave Mr. Obama with the task of framing a broader strategy that involves Saudi Arabia, the Arab League and the United Nations, just to start.