RPT-Obama faces limited options in Iraq crisis, doubts over air strikes

(Repeats Insight with no change to headline or text)

By Matt Spetalnick and Mark Hosenball

WASHINGTON, June 13 (Reuters) - Two and a half years after President Barack Obama disentangled America from a long, unpopular war in Iraq, his options for helping the Iraqi government stave off a militant onslaught are slim as doubts simmer over whether even punishing air strikes would be effective.

He will announce in coming days how far he is willing to go in responding to the crisis in Iraq, where militants are sweeping south towards the capital Baghdad in a campaign to recreate a large mediaeval Islamic caliphate spanning Iraq and Syria.

While Obama has ruled out sending combat troops, U.S. officials say options under consideration include air strikes on Sunni insurgents threatening the Shi'ite-led government, accelerated delivery of weapons and expanded training of Iraqi security forces. The U.S. already has increased intelligence-gathering flights by drone aircraft over Iraq, officials said.

There is growing skepticism both inside and outside of the administration whether Washington has the will, let alone the power, to halt Iraq's slide into a civil war that could tear it apart. The collapse of Iraq's U.S.-trained army in the north this week has compounded concerns that fast-moving events are unfolding beyond America's ability to control them, say officials.

"It is a colossal mess," said one senior U.S. official.

Hoping to mitigate the risk of a failed U.S. response, the administration may opt for a phased approach, first trying to shore up Iraqi forces and possibly resorting to more direct military action if the situation deteriorates further, according to a source familiar with the White House's thinking.

The biggest questions center on whether the United States will carry out air strikes, either with warplanes or unmanned drones, against militants of the Islamic State in Iraq and the Levant, or ISIL, which moved swiftly to seize the northern cities of Mosul and Tikrit this week and now threaten Baghdad.

Such attacks, an option the Pentagon described on Friday as "kinetic strikes", could be launched from aircraft carriers or from the sprawling U.S. air base at Incirlik in Turkey. The carrier USS George H.W. Bush and its strike group are already "in the region," the Pentagon said on Friday.

While a U.S. air assault could send a tough message to ISIL forces about Washington's commitment to the survival of the besieged Iraqi government, national security officials are raising concerns about the U.S. ability to target roving bands of insurgents and seriously damage their fighting capabilities.