Possible U.S. action on Iraq requires clearer picture: Pentagon

The Iraqi government has requested U.S. airstrikes to help it put down the advancement by Sunni insurgents, but senior U.S. defense officials said Wednesday that a clearer picture of the situation on the ground as well as clear objectives is required before any airstrikes or other military intervention.

Martin Dempsey, chairman of the Joint Chiefs of Staff, told a Senate hearing that while he shares alarm over the Iraq situation, he could recommend military force only "once I'm assured we can use it responsibility and effectively," the Pentagon said in a press release.

Dempsey's remarks came five days after President Barack Obama said he had asked his national security team for a range of options for helping the Iraqi government thwart the rapid Sunni insurgent sweep through much of the country's north and west, posing the threat of reprisals from Shiites.

Dempsey said various indistinguishable forces are on the ground in northern Iraq, including the insurgents who threaten Baghdad -- known as the Islamic State in Iraq and Syria, or ISIS, and the Islamic State of Iraq and the Levant, or ISIL -- as well as former Baathists and other disenfranchised groups.

"Until we can actually clarify this intelligence picture, the options will continue to be built and developed and refined and the intelligence picture made more accurate, and then the president can make a decision," Dempsey said.

"It's not as easy as looking at an iPhone video of a convoy and then immediately striking," he added.

Meanwhile, Defense Secretary Chuck Hagel told the hearing that the Pentagon is providing the president with different options, but that any U.S. military intervention in Iraq, including airstrikes, would require clear objectives.

"There has to be a reason for those, there has to be an objective," he added.

A number of U.S. lawmakers, as well as former military officials, have called for airstrikes against the Sunni insurgents, who have taken over Iraq's second-largest city of Mosul and other towns on their rapid push southward toward Baghdad.