The WSJ reports,"the radical Sunni militia that has plunged Iraq into chaos bragged on Sunday that it had executed hundreds of Shiite Iraqi soldiers", even as the Obama administration said it is preparing to open direct talks with Iran on how the two longtime foes can counter the insurgents.
The U.S.-Iran dialogue, which is expected to begin this week, will mark the latest in a rapid move toward rapprochement between Washington and Tehran over the past year. It also comes as the U.S. and other world powers try to reach an agreement with Iran by late July to curb its nuclear program.
The U.S. and Iran have publicly committed in recent days to provide military support if requested to Iraqi Prime Minister Nouri al-Maliki and help his government repel an offensive the Islamic State of Iraq and al-Sham, or ISIS, has launched against Baghdad and other major Iraqi cities over the past week.
The U.S. over the weekend repositioned military equipment throughout the region and sent an aircraft carrier to the Persian Gulf as President Barack Obama awaited options for possible military action.
Iraqi officials said on Sunday that ISIS had taken control of Tal Afar in northwest Iraq, where thousands of U.S. and Iraqi forces once fought. The U.S. had hailed the city as a model of its "clear, hold and build" strategy in Iraq.
The possible depth of the ISIS threat became clearer on Sunday when photos were posted on a Twitter account associated with ISIS claiming to show Sunni militants carrying out a mass execution of captured Iraqi Shiite soldiers, raising the prospect of a broader sectarian war in Iraq.
The photographs, accompanied by captions boasting that as many as 1,700 soldiers had been executed, underscored the mounting sectarian animosity fueling the fighting between Sunni extremists and Mr. Maliki's Shiite-dominated government.
If the claim of carrying out mass executions in Iraq is true, pressure could increase on Shiites to retaliate, raising the prospect of a wave of reprisal killings reminiscent of the bloodshed that convulsed Iraq in the years following the U.S.-led invasion of Iraq in 2003.
Neither the alleged death toll nor the identity of the purported victims could be verified independently.
But Ahmed Abdullah Al Jibouri, the governor of Salah Al Din province, where the mass atrocity supposedly took place, said that ISIS had captured "hundreds" of Iraqi military personnel and Air Force Academy students and is believed to have executed them.
Mr. Jibouri said that the exact number of dead was unknown, since government officials have been unable to reach the alleged sites of the massacre.
In Washington, State Department spokesperson Jen Psaki said the U.S. couldn't confirm reports of the massacres but called the claim by ISIS "horrifying and a true depiction of the blood lust that these terrorists represent."
U.S. officials said it is imperative for Washington to discuss the security situation in Iraq with Iran and other regional powers in a bid to better coordinate a response against ISIS.
Secretary of State John Kerry communicated Washington's strategy to his Iraqi counterpart, Hoshyar Zebari, in a phone call on Saturday, according to the State Department.
Iranian President Hasan Rouhani said on Saturday that his government was open to cooperating with the U.S. in Iraq and that he exchanged letters with President Obama.
The White House's engagement with Iran on Iraq offers both opportunities and risks, said U.S. defense officials and Arab diplomats.
Iran, a majority Shiite country, has served as Mr. Maliki's closest Mideast ally and has mobilized Tehran's military and religious establishment to support their coreligionists in Iraq in recent days. Iran's elite military unit, the Islamic Revolutionary Guards Corps, has an extensive presence inside Iraq, said U.S. officials, and has trained Shiite militias that have joined the Iraqi army in fighting ISIS.
U.S. officials say the IRGC trained many of the largest Shiite militias going back to the Iraq war and maintain contacts. These include the Mahdi Army, Kata'ib Hezbollah, and Asab Ahl al-Haq.
Iran has publicly denied sending forces to fight in Iraq and has said it would give Iran military assistance if Iraq asked.
Even some of Mr. Obama's harshest critics in Washington voiced support on Sunday for coordinating the U.S.'s military response in Iraq with Tehran's. They argued that ISIS poses a much greater near-term threat to the U.S.'s national-security interests than does Iran.
"Why did we deal with Stalin? Because he was not as bad as Hitler," Sen. Lindsey Graham (R., S.C.) said Sunday on CNN. "The Iranians can provide some assets to make sure Baghdad doesn't fall."
A number of U.S. defense officials, however, said Iran has a drastically different vision for Iraq than does the U.S. The Iranian government has also supported Mr. Maliki's policies of marginalizing Iraq's minority Sunni population politically and economically, which has fueled support for the ISIS's military operations in the Sunni regions of Iraq.
Any U.S. military campaign in Iraq that is seen as allied with Iran's and the Shiite majority's risks further polarizing the country, said these officials. It could also alienate Washington's allies in Sunni-dominated countries like Saudi Arabia, Turkey and Jordan.
"This is a case where the enemy of our enemy is still our enemy," said a U.S. defense official who has worked extensively in Iraq. "Any shared interests in Iraq are limited."
U.S. allies in Israel and the Middle East are also concerned that any cooperation between Washington and Tehran on Iraq could complicate the nuclear negotiations.
"Iran and the U.S. are the only two countries with the power to end Iraq's crisis in a peaceful way," tweeted Hamid Aboutalebi, a top political adviser of Mr. Rouhani, on Sunday.
For Iran, the incentive to cooperate with the U.S. on Iraq goes further than just a desire to improve relations with the U.S., many observers say. ISIS is one of the biggest security threats Iran has faced since the U.S. invaded Iraq in 2003, establishing military bases across the Islamic Republic's borders.
"Iran is definitely willing to cooperate with the U.S. over Iraq because the threat it's facing is one of existential national security," said Saeed Leylaz, a political analyst close to the government, in a phone interview from Tehran.
