An Iranian soldier from Quds Force, the elite overseas branch of Iran’s Revolutionary Guard Corps, was killed in Iraq fighting Sunni extremists, reported news agencies affiliated with Iran’s government on Monday.

Alireza Moshajeri, referred to simply as ‘pasdar’ or ‘fighter,’ marked Iran’s first reported casualty in what is shaping up to be a Sunni-Shiite sectarian war next door, reported the news agencies.

As life returns to an uneasy version of normal in Mosul, the response from local residents to the city’s capture by ISIS, a radical Islamist group, has been surprisingly positive. Multiple Sunni residents inside Mosul who spoke with The Daily Beast by phone reported being glad to be rid of the predominantly Shia government security forces, and so far pleased with life under the ISIS occupation. That may change soon if ISIS begins to rule with the brutality they have displayed in Syria, but by keeping the residents of Mosul happy for now ISIS is buying time to increase its power and local support, which will make things even harder for the Baghdad government if it tries to take the city back.

In response to the recent news from Mosul, an Iraqi citizen recalled the story of a friend from Diyala Province. “He told me, ‘It was the same for us in 2007. We were very happy when ISIS took over the area and drove the Iraq Army out and at first they behaved very well. It was only after a month that they started killing us.’”…

In the east Mosul neighborhood of Al-Sumer, a call for recruits to support the new rebellion brought hundreds of young men to the streets to sign up. With the vast trove of government arms collected and more recruits joining the ISIS offensive, the Iraqi Army, if it tries to retake the city, may find an even larger and more entrenched force in Mosul than the one that threw them out in the first place.

In an interview, Qubad Talabani—the Kurdish government’s incoming deputy prime minister and the son of Iraq’s president, Jalal Talabani—said Kurdish leaders do not seek the dissolution of Iraq, but that it’s happening nonetheless.

“Iraq, in a sense, has broken apart from us,” he told The Daily Beast. “Geographically we practically have to cross another country to get to Baghdad. We have to cross through territory that is governed and secured by forces that are not loyal to the federal government in Baghdad.”…

For years, politicians and analysts have warned that Iraq—a country formed in 1920 by the world’s great powers from three distinct ethnic and confessional regions—would eventually break apart.

The closer ISIS gets to the Iraqi capital, and the sacred Shi’ite shrine of the Mosque of the Golden Dome in the city of Samarra, the more likely Iran will feel that it has no choice but to intervene. Iranians, says Philip Smyth, an expert on Shi’ite militias at the Washington Institute for Near East Policy, sees ISIS “as an existential threat to the Shi’ite population of Iraq, and are trying to grab the bull by the horns.” When ISIS’s predecessor, the Islamic State of Iraq, attacked the shrine in 2006 it unleashed a spasm of sectarian violence that resulted in the deaths of tens of thousands of Iraqis of both sects, and left more than four million displaced.

But an Iranian military presence would not only alarm Iraqi Sunnis, it would be a major affront to the U.S.’s Sunni allies in the Gulf, like Saudi Arabia, Bahrain and the United Arab Emirates. “When you start seeing Iranian aircraft, [Iranian Revolutionary Guard Corps] forces on the ground, Iranian advisors training the Iraqi military, it could easily devolve into a regional conflagration,” says Smyth. “It’s not like Riyadh wants to back ISIS, but what are they going to do when they see a mobilization like this, and no other outside force to quell it?”…

Iran’s possible role has already evolved beyond Samarra. ISIS must be stopped, says Smyth. The U.S. may not be willing to intervene militarily, but it may not have a choice. The U.S., he says, cannot afford to let Iran take the lead in stopping ISIS. “Both [Iran and ISIS] are bad for American policy and American interests in the region.” Sectarian war, however, will be bad for all concerned.

Mohamed Elibiary, a controversial figure and member of DHS’s Homeland Security Advisory Council (HSAC), discussed what he described as the “inevitable” return of a Muslim caliphate Friday on Twitter.

“As I’ve said b4 inevitable that ‘Caliphate’ returns,” Elibiary tweeted in response to a question about the terror group Islamic State of Iraq and the Levant (also known as ISIS, or the Islamic State of Iraq and al-Sham), which is currently seeking to overthrow the Iraqi government and instate strict Sharia law in the country.

“Choice only whether we support [European Union] like Muslim Union vision or not,” wrote Elibiary, who has “advised numerous federal, state and local law enforcement organizations on homeland security-related matter,” according to his biography on DHS’s website.

The extremist groups dominating the fighting are beginning to take their war beyond the two countries that they now freely traverse. In January, ISIS carried out a car-bomb attack in Beirut near the offices of Hezbollah, the Lebanese militant group that has been fighting on behalf of Assad. The Nusra front has also carried out attacks in Lebanon. Meanwhile, the number of Syrian refugees who have fled to that nation exceeds twenty per cent of its population, which is not something that a state as weak and as fractious as Lebanon can be expected to sustain. In Jordan, the presence of half a million Syrian refugees is putting an enormous strain on the fragile monarchy.

The revolutionary government of Iran looms ominously over it all. Iran has been decisive in supporting Assad, and its influence over Maliki, never small, has increased enormously since the departure of the last American forces in Iraq, in December of 2011. During the war, Iranian agents trained, armed, and directed a network of Shiite militias, which killed hundreds of American and British soldiers. Those same militias are evidently being readied to confront the Sunni onslaught in Iraq; thousands of their members have already been fighting for Assad in Syria. Iran’s intervention in Syria has also alarmed Saudi Arabia and Turkey, which have poured in guns and money to help the rebels. It is not difficult to imagine a multinational war, fought along a five-hundred-mile front, and along sectarian lines, waged ultimately for regional supremacy…

Within a day after sweeping into Mosul, ISIS militants freed thousands of prisoners, looted bank vaults, and declared the imposition of Sharia law. From now on, the group said, unaccompanied women were to stay indoors, and thieves would be punished by amputation. The “divine conquest” of Mosul by a group of Islamic extremists is a bitter consequence of the American invasion. For now, there seems to be very little we can do about it.

What if U.S. troops had remained, with or without protections? Would it have proven decisive in shielding Iraq against the current onslaught? There is little doubt that the presence of American counterterrorism advisers, providing intelligence to assist Iraqi forces in targeting al Qaeda in Iraq (which became the Islamic State of Iraq and Syria, or ISIS), would have helped keep pressure on the network. Air support and more robust training assistance would also have improved the capabilities of the Iraqi army – or, at the very least, slowed the degradation of these capabilities. It was precisely for these reasons that Obama was willing to consider leaving some U.S. forces in Iraq.

But the idea that such a force would have completely stopped the jihadists is a fantasy. In 2011, when the Syrian protest movement was only just beginning to morph into a nationwide insurgency, few analysts anticipated the sheer scale of the spillover into neighboring Iraq. The enormous boon this created for ISIS could have overwhelmed Iraqi counterterrorism capabilities even if U.S. advisers had remained.

And, crucially, a hypothetical follow-on force would have done little to ameliorate the political dynamics underlying the current crisis. The litany of Maliki’s failures to accommodate Sunni aspirations is well known: his failure to live up to power-sharing promises made in 2010; his extra-constitutional abuses of power; his persecution of Sunni politicians; his failure to sustain ties with Sunni tribes in western Iraq; his refusal to follow through on commitments to integrate “Awakening” fighters into Iraqi security forces; and his heavy-handed response to Sunni political protests in Anbar province last year.

It’s widely agreed that the collapse of Iraq would be a disaster for American interests and security in the Middle East and around the world. It also seems to be widely assumed either that there’s nothing we can now do to avert that disaster, or that our best bet is supporting Iran against al Qaeda. Both assumptions are wrong. It would be irresponsible to embrace a premature fatalism with respect to Iraq. And it would be damaging and counterproductive to accept a transformation of our alliances and relationships in the Middle East to the benefit of the regime in Tehran. There is a third alternative…

This would require a willingness to send American forces back to Iraq. It would mean not merely conducting U.S. air strikes, but also accompanying those strikes with special operators, and perhaps regular U.S. military units, on the ground. This is the only chance we have to persuade Iraq’s Sunni Arabs that they have an alternative to joining up with al Qaeda or being at the mercy of government-backed and Iranian-backed death squads, and that we have not thrown in with the Iranians. It is also the only way to regain influence with the Iraqi government and to stabilize the Iraqi Security Forces on terms that would allow us to demand the demobilization of Shi’a militias and to move to limit Iranian influence and to create bargaining chips with Iran to insist on the withdrawal of their forces if and when the situation stabilizes…

Throwing our weight behind Iran in the fight against al Qaeda in Iraq, as some are suggesting, would make things even worse. Conducting U.S. airstrikes without deploying American special operators or other ground forces would in effect make the U.S. Iran’s air force. Such an approach would be extremely shortsighted. The al Qaeda threat in Iraq is great, and the U.S. must take action against it. But backing the Iranians means backing the Shi’a militias that have been the principal drivers of sectarian warfare, to say nothing of turning our backs on the moderates on both sides who are suffering the most. Allowing Iran to in effect extend its border several hundred kilometers to the west with actual troop deployments would be a strategic disaster. In addition, the U.S. would be perceived as becoming the ally of the Islamic Republic of Iran against all of the forces of the Arab and Sunni world, conceding Syria to the Iranian-backed Bashir al-Assad, and accepting the emergence of an Iranian hegemony soon to be backed by nuclear weapons. And at the end of the day, Iran is not going to be able to take over the Sunni areas of Iraq—so we would end up both strengthening Iran and not defeating ISIS.

We face a simple choice: We can either rejoin our demoralized Iraqi partners in the fight against ISIS or we can watch as this Al Qaeda franchise solidifies its control over several million Iraqis and Syrians, completes its plundering of military bases and continues to build up, train and equip an honest-to-goodness military.

Rejoining the fight means immediately sending air support; intelligence, surveillance, and reconnaissance assets; air transportation; Special Operations forces; training teams; and more military equipment back into Iraq. It does not mean re-invading Iraq.

Immediately sending air support and Special Forces to Mosul might shock ISIS and embolden the population enough to rout the jihadis from the city. But if it does not, the Iraqi Security Forces may well prove unable to regain Mosul on their own.

In that case, a small contingent of U.S. ground forces would be required.

Manned airstrikes may be useful against the ISIL lines of communication. But they are of limited use in urban environments. Whatever mix of manned or drone strikes is employed, we and the Iraqis will need good current intelligence. As during the U.S. troop surge in Iraq in 2007, Iraqis will need Americans to help plan and execute those operations. So there may be a need for American intelligence and fire control personnel on the ground. If so, President Obama would be correct to insist that Mr. Maliki quickly sign a Status of Forces agreement to give our military standard immunities that all our overseas forces have…

It is time for both American political parties to cease their ritualistic incantations of “no boots on the ground,” which is not the same as “no combat forces.” Of course Americans are reluctant to re-engage in Iraq. Yet it is President Obama’s unhappy duty to educate them about the risks to our interests posed by the unfolding drama in Iraq.

The crisis in Iraq is a flashing warning light about the dangers of a reductionist national security policy that sends a signal of weakness to friends and enemies abroad. The most immediate crisis is in Mesopotamia. But we can be sure that the Taliban in Afghanistan are watching closely to see if the withdrawal of American forces comes to mean American indifference. Beyond the Hindu Kush, east across the Zagros Mountains and to the north of Iraq, hard-eyed men in Beijing. Tehran and Moscow are also calculating the implications of our handling of this crisis. The stakes could not be higher.

Despite the absurd arguments from the war-drum crowd that we needed to spend even more time in Iraq, we know that’s not a rational response. The Iraqis are not children, and their factional issues are theirs to deal with, not ours. Additional actions in Iraq not only would cost more money that we really can’t afford, but any sort of military action (even absent ground troops) can risk American lives. The perfectly reasonable resistance to further military action is a reflection of the grasp of sunken costs in Iraq. The trillions of dollars spent in Iraq and the loss of American lives and the permanent injuries so many have suffered didn’t liberate the country. There is no rational reason to believe that additional actions will result in a better outcome.

I can’t even fathom what it must feel like to be in the position of these veterans, to have lost arms, legs and friends in Iraq and to watch what’s happening now. But we can’t turn lies (the reasons for the Iraq war) into something noble by continuing to throw money and people at Iraq to “fix” it. I don’t know how to fix the pain, emotional and physical, veterans must feel over Iraq’s crumbling, but I do know that we can’t make it better by spreading that pain to even more veterans. That would be the likely outcome of additional military action in Iraq.

To extricate the United States from the unpopular war he had inherited from his predecessor, President Nixon sold out the South Vietnamese. Yet by simultaneously reaching an accommodation with China, he managed at least one trick: By the time Saigon fell, Nixon had reduced by one the roster of countries that Washington counted as problems or threats. He thereby salvaged a modicum of advantage acutely relevant to the as-yet-undecided Cold War.

Obama is not guilty of consciously selling out a former ally. To extricate the United States from an equally unpopular war that he inherited from his predecessor, he merely cut Iraq loose. Perhaps he had little alternative but to do so. Yet in terms of implications, Obama’s actions are much the same as Nixon’s: Iraqi problems are no longer our problems…

One glimmer of opportunity remains, in terms of daring and audacity the closest thing to a Nixonian gambit: Ending the U. S. diplomatic estrangement from Iran could yield a strategic realignment comparable to that produced by the opening to China, its effects rippling across the greater Middle East. There, rather than in misguided proposals for renewed U.S. military action, lies Obama’s chance to demonstrate that he has grasped the lessons that Iraq (along with Vietnam) has to teach. One can imagine Nixon himself relishing the prospect.