'Horrible choices' for US next move in Iraq
The fall of Mosul and Tikrit to Sunni Islamist forces led by the Islamic State in Iraq and the Levant (ISIS) has once again put the ongoing unrest in Iraq - and the consequences of the US invasion and subsequent withdrawal from the country - back into the headlines.
While there's been plenty of hand-wringing and finger-pointing - President Barack Obama is to blame, no he's not, George W Bush is at fault - constructive suggestions about where the US can go from here are much scarcer.
While most commentators agree that something has to be done, opinions diverge as to the next step for US policymakers.
It's time for the US to get more involved, writes Washington Institute for Near East Policy fellow Michael Knights.
"With ISIS forces capturing city after city, Washington has to do more (and quickly) to prevent the loss of government in Iraq," he argues in Foreign Policy magazine. "Intensified US on-the-ground mentoring of Iraqi military headquarters and perhaps US air strikes might also be needed to reverse the collapse of Iraq's military."
While Mr Obama may feel bound by his campaign promise to end the war in Iraq, he writes, circumstances dictate a change of policy.
"The Middle East could see the collapse of state stability in a cross-sectarian, multiethnic country of 35 million people that borders many of the region's most important states and is the world's fastest-growing oil exporter," he writes. "Any other country with the same importance and the same grievous challenges would get more US support."
He concludes: "Washington doesn't have the luxury of treating Iraq as a special case anymore."
The editors of Bloomberg View caution that this week's developments expose the "real possibility" that Iraq could be disintegrating, "with transnational badlands under ISIS's control that serve as a base for the training and radicalisation of foreign volunteers".
US "personnel and equipment" are engaging militants in Nigeria and Somalia, they note. "US interests in Iraq are worth at least as much of a commitment."
In the New York Times, Harvard Kennedy School fellow Nussaibah Younis agrees that the US must provide military aid to defend Baghdad and help Iraqi forces retake Mosul.
In the long term, however, he says that won't be enough. In order to undermine the growing Iraqi insurgency, the US must urge Iraq to address the underlying political grievances of the rebelling Sunni minority. "An influx of American weapons will only add fuel to the fire consuming the country," he writes.
The US must urge Iraqi Prime Minister Nouri Maliki from pushing for dictatorial emergency powers, and instead institute reforms to incorporate Sunnis into the government. In addition, Iraqi counter-insurgency efforts should be sensitive to the Sunni civilian population.
"If the Iraqi Army sends Shiite militant groups or Kurdish forces to the heart of Sunni-dominated Mosul, or if it carpet-bombs the city and arbitrarily arrests or kills groups," he writes, "it will alienate the hearts and minds essential to winning this battle."
Charlie Cooper of the think tank Quilliam agrees that Mr Maliki needs to "challenge the jihadists ideologically" by reaching out to Sunnis.
"This is the well from which most ISIS fighters are drawn," he says. "Taking a purely heavy-handed approach will just feed into the jihadist propaganda."
If the New Yorker's Dexter Filkins take on Mr Maliki is accurate, however, the Iraqi president may be unwilling to budge.
"Maliki is a militant sectarian to the core," he writes. The US was able to restrain the prime minister's more dangerous tendencies when its military was on the ground there, but that has all changed.
"Time and again, American commanders have told me, they stepped in front of Maliki to stop him from acting brutally and arbitrarily toward Iraq's Sunni minority," he writes. "Then the Americans left, removing the last restraints on Maliki's sectarian and authoritarian tendencies."
This is why, Filkins says, it was important for the US to have kept some military on the ground in Iraq - a view echoed by former Bush-era ambassador to Iraq, Zalmay Khalilzad.
"What the Americans left behind was an Iraqi state that was not able to stand on its own," Filkins argues.
The US is probably better off just trying to force Mr Maliki out of office, writes Commentary magazine's Max Boot:
Maliki has presided over the disintegration of Iraq. He doesn't deserve a third term. The country desperately needs a new leader. Until a change of leadership happens, there is little point in sending more US aid which, if Mosul is anything to go by, is likely to wind up arming the insurgents.
The Washington Post's David Ignatius says Mr Obama must start by raising awareness in the US of the growing threat in Iraq. Then, he argues, the president must solve the civil war in Syria if it wants to prevent violence from engulfing Iraq:
The administration is finally developing a serious strategy for Syria, which will include a CIA-trained guerrilla army to fight both President Bashar al-Assad and al Qaeda extremists. In addition, (if skittish Arab allies agree), US Special Operations forces will train Free Syrian Army units to create a stabilisation force for liberated areas. If the ambitious plan moves forward, the hope is to train 9,600 fighters by the end of this year.
Lehigh University Prof Henri J Barkey also thinks ending Syria's civil war is the key to peace in region.
"The perception of Washington policymaking in Syria as dithering and less-than-professional has arguably spread throughout the region," he writes for the American Interest. "The administration can begin to reverse this image if it is willing to encourage the region to come up with its own solution. That effort would have to start in consultation with Turkey and Saudi Arabia, and it would have to include Iran as well in the end."
The American Conservative's Rod Dreher takes an opposite view - greater involvement in the Syrian civil war will only make matters worse, as US weapons could end up in the hands of anti-Western militants -a similar fate to some of the arms the US gave Iraq :
A decade after American troops invaded Iraq as a response to al Qaeda's 9/11 attack - a decade that saw nearly 4,500 US deaths, tens of thousands of American casualties, 134,000 Iraqi civilian deaths, and cost the US taxpayer at least $1.7 trillion - the capital of that woebegone country is in danger of falling to Islamist berserkers who are more radical than al Qaeda. Yet the US is continuing to arm and train Syrian rebels. We never learn.
Doing nothing is an option, writes the Federalist's David Harsanyi, despite the obvious criticism that it likely would mean that "more than 4,400 U.S. troops and over $700 billion had been wasted in a war that ended but was not won".
But would another 4,000 deaths fix things, he asks. "If a decade of nation building brought us this, what could we possible gain by seriously re-engaging?"
He concludes: "It's difficult to understand how spending another five or ten years sorting out a sectarian civil war can possible be in our best interests."
He says all of the choices the US is presented with are horrible.
This is likely one thing everyone can agree on.