BAGHDAD — Kurdish forces took control of most of Iraq’s largest dam Sunday as the largest U.S. deployment of air power in the campaign helped reverse some of the gains made by Islamic State militants in the north.
The U.S. widened its airstrikes over the weekend and used bombers for the first time since the offensive began Aug. 8 to help secure the dam near Mosul, Iraq’s largest northern city, that had been seized by the insurgents.
President Barack Obama for the first time authorized strikes for the purpose of protecting critical infrastructure, not just U.S. personnel or threatened Iraqi minorities. He told Congress in a letter the action is consistent with the mission to safeguard Americans and U.S. facilities.
Kurdish forces, also known as the peshmerga, will have full control of the Mosul Dam in “just a matter of time,” Fuad Hussein, the chief of staff for Kurdish Regional Government’s president Massoud Barzani, said in a phone interview. Kurdish forces were dismantling bombs placed near the main gates of the dam, he said. Nineveh provincial council member Hisham Brefkani also said the peshmerga controlled the dam except for “some pockets.”
The weekend action marked an escalation of U.S. involvement. Until then, the few dozen strikes over the past week had been limited to protecting U.S. personnel near Erbil, the Kurdish regional capital, and attacking militants around Mount Sinjar, where thousands of Yezidi civilians had been trapped seeking refuge.
While those strikes were aimed at stopping the advance of Islamic State forces, the weekend attacks near the Mosul dam marked the first effort at rolling back the militants’ gains.
In 14 strikes Sunday, the U.S. destroyed or damaged Islamic State armed vehicles, Humvees, armored personnel carriers and a checkpoint near the Mosul dam, by using a mix of fighter jets, bombers and armed drones, according to a statement from U.S. Central Command in Tampa, Fla.
Kurdish fighters, along with regular Iraqi forces and U.S. fighter jets, are seeking to rein in the Sunni insurgents known as the Islamic State who have rampaged through OPEC’s No. 2 oil producer, seizing border posts, beheading foes and targeting dams.
“There was no fierce fighting” involved in the push to control the dam, Mr. Brefkani said by phone.
The dam is the most important asset the Islamic State captured since taking Nineveh province in June. The militants also control several oil and gas fields in western Iraq and eastern Syria, generating millions of dollars in daily revenue to help fund the caliphate it announced and strengthen its grip on territory it has seized.
Although the Defense Department declined to name the aircraft involved in the latest strikes for operational reasons, the weekend offensive marked the largest deployment of U.S. aircraft in the 11-day-old campaign, according to a U.S. defense official who spoke on condition of anonymity.
“These air operations are for the sole purpose of helping the Iraqi military and Kurdish forces to defeat the militants around strategic sites,” Theodore Karasik, director of research at the Institute for Near East and Gulf Military Analysis in Dubai, United Arab Emirates, said in a phone interview. “The U.S. must hit critical equipment and economic assets to weaken the Islamic State’s grip on territory.”
In authorizing the initial airstrikes Aug. 7, Mr. Obama tied expanded U.S. action to the formation of a more inclusive government capable of easing sectarian and ethnic divisions.
That prospect was strengthened last week, when Prime Minister Nouri al-Maliki agreed to step aside after his backing at home and overseas had crumbled. Prime Minister-designate Haidar al-Abadi has until mid-September to form a less divisive government better able to fight the Sunni militants.
Even so, the Iraqi government expressed a new frustration with the U.S. on Sunday by accusing it of conducting airstrikes without its approval and violating Iraq’s sovereignty.
“It was noticed in recent days that war jets have violated the skies of the country, arming local sides without our approval,” according to al-Iraqiya state television, which cited a statement issued by the chief of armed forces.
Mr. Obama, in a letter Sunday to House Speaker John Boehner, said the strikes near the Mosul dam “are being undertaken in coordination with the Iraqi government.”