Iraqi Kurds seize Mt. Sinjar from Islamic State in major victory

Iraqi Kurdish fighters have broken the Islamic State's siege on Mount Sinjar in northern Iraq with the help of US-led airstrikes, freeing hundreds of people from the country’s Yazidi minority who were trapped there for months, a senior Kurdish official said Thursday.

The development marks a major victory for the Kurdish fighters, known as peshmerga, and the US-led coalition against the self-described Islamic State (IS). The plight of the Yazidis, in addition to IS attacks across Iraq's semiautonomous Kurdish region, prompted the United States to begin airstrikes in the country in August.

The liberation of Mount Sinjar was part of a massive offensive peshmerga forces launched earlier this week against IS militants in northern Iraq. The Kurdish fighters recaptured a large swath of territory in the region over the last few days, reports The New York Times.

Masrour Barzani, the head of the Kurdistan Regional Security Council, called the operation “the single biggest military offensive against [IS], and the most successful.”

A surge of airstrikes from the US-led coalition backed the Kurdish ground offensive. On Tuesday night, coalition forces launched 48 airstrikes near Mount Sinjar in the largest barrage yet, two US defense officials told CNN.

The New York Times called it a “successful demonstration of President Obama’s strategy for battling the extremist group: American air power combined with local forces doing the fighting on the ground.”

The Kurdish fighters' success in opening up a corridor on Mount Sinjar was, according to The Associated Press, an “incremental step” in their push to retake the town of Sinjar at the foothills of the mountain.

Mr. Barzani said the corridor enables Kurdish fighters to gain direct access to the Yazidis on the mountain and to provide them with humanitarian support.

"All those Yazidis that were trapped on the mountain are now free," Barzani said, according to Reuters.

'Disruptive to their planning'

The siege began in August when IS forces surrounded the mountain and the tens of thousands of people from the Yazidi religious minority who sought refuge there. The brutal assault sparked Obama into action, leading him to launch airstrikes and humanitarian airdrops.

Stranded and at risk of being slaughtered, many Yazidis were eventually airlifted to safety or fled on foot to Syria. CNN reports that only a few hundred Yazidis were left on the mountain.

In addition to supporting peshmerga troops on the ground in Iraq, US airstrikes have also killed three IS leaders in recent weeks, the Pentagon confirmed Thursday.

“It is disruptive to their planning and command and control,” Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, told the Wall Street Journal. “These are high-value targets, senior leadership.”

While the US-led air campaign in Iraq remains a joint effort with coalition forces, the US military appears to be largely going it alone in Syria. A Reuters investigation found that nearly 97 percent of the strikes in Syria this month have been carried out by the US alone.

That accentuates a shift that began shortly after the start of the campaign in late September, when U.S. allies carried out 38 percent of the strikes. The percentage quickly dropped to around 8 percent in October and 9 percent in November, according to Reuters calculations based on the data.

U.S. officials are keen to prevent the coalition from fraying over concerns about the air campaign's direction. Some allies have long worried the air strikes might unintentionally bolster Syrian President Bashar al-Assad by striking a common enemy, sources said. Others in the region are also saying privately that the U.S.-led campaign against Sunni extremists needs to do more to help Sunni Muslims.