The crisis now unfolding in Iraq poses a major and urgent challenge to the interests of the United States, Japan, and their allies. It threatens to further destabilize an already chaotic Middle East. It has caused oil prices to rise on concerns over not only Iraq's current production, but worries over its future production, which has been projected to rise to meet increases in global demand in coming years. The conflict there -- which pits the radical Sunni extremists of the "Islamic State in Iraq and al-Sham" (ISIS) or just "Islamic State," against other factions -- has also proven to be a magnet for so-called "foreign fighters," who will return to their homes from the battlefield hardened by fighting experience and equipped with support networks. And the conflict threatens to roll back Iraq's fragile but hard-won democratic gains.

For the United States, however, the crisis is particularly disheartening. The areas being overrun by ISIS were, during the last decade, secured at great cost and sacrifice by American-led forces, and the Iraqi security forces melting away in the face of the jihadist onslaught were trained and equipped at U.S. expense. As the situation deteriorates, toward perhaps the domination of Iraq by ISIS and its allies or the fragmentation of Iraq into warring ethnic enclaves, it has reinforced in the West a paralyzing sense that Middle East conflicts are simply intractable and Western intervention therefore inevitably fruitless. If Washington is to achieve its goals in Iraq and beyond, it must therefore overcome not only the rapidly escalating challenges on the ground, but its own doubts about engagement and leadership in the Middle East.

THE ROOTS OF THE CRISIS

The Iraqi crisis burst into the headlines in June 2014 when ISIS forces captured Iraq's second-largest city, Mosul. But the conflict had been brewing long before that. After Iraq's parliamentary elections of 2010, the so-called "Irbil Agreement" produced a power-sharing government led by Prime Minister Nouri Kamal al-Maliki and his Shiite "State of Law" party and including other major Sunni, Shiite, and Kurdish factions. However, underlying disputes between those factions were never resolved, and the government began to unravel as soon as American troops withdrew in December 2011.

Immediately following the U.S. withdrawal, the Iraqi government sought to arrest and prosecute major Sunni figures, including Vice President Tariq al-Hashimi and, later, Finance Minister Rafi al-Issawi. This marked the beginning of Iraq's up-and-down descent into instability, which American efforts to broker political compromises and a pan-sectarian effort to oust Maliki in March 2012 could not head off, and which was further exacerbated by disputes between Baghdad and the Kurdish Regional Government over the sharing of oil revenues and other matters.

Mounting Sunni unrest in Iraq, combined with the conflict across the border in Syria, provided fertile ground for the activities of ISIS. The group began to re-gather strength in 2013 and overran Fallujah late that year, setting the stage for its metastasis into the most serious challenge in years to the security and territorial integrity not only of Iraq, but -- given ISIS's refusal to recognize modern national boundaries -- of neighboring countries as well.

In the United States, much of the discussion of the Iraqi crisis has centered on the decisions by President Bush to invade Iraq in 2003, and by President Obama to withdraw all U.S. troops in 2011. The Iraq War initially enjoyed significant popular and political support in the United States, which faded as the fighting progressed. According to Pew polling, 72 percent of Americans supported the war when it began; by 2005-2006, Americans were evenly split on the war, and by February 2008 -- as U.S. presidential elections began to heat up -- only 38 felt that using military force in Iraq had been the right decision, even though 47 percent felt U.S. troops should remain in Iraq until it was stabilized and 48 percent felt that the war was going very or fairly well, likely influenced by the success of the so-called "surge" of U.S. troops in 2007.

Nevertheless, public dissatisfaction with the Iraq war was a key factor in the 2008 U.S. elections and was seized upon by then-Senator Barack Obama, for whom opposition to the Iraq war -- which he pilloried as a "dumb war" -- was long-held and a central campaign tenet. It came as little surprise, therefore, when President Obama withdrew all U.S. troops from Iraq in December 2011. While he had sought an extension of a limited troop presence after that date, only to be rebuffed when Iraq refused to grant U.S. forces the necessary legal immunities, the negotiation was hampered by mixed signals sent by the White House. The withdrawal was subsequently trumpeted as a signature achievement by President Obama, who disavowed in a 2012 foreign policy debate the effort to obtain the troop extension. Just as significantly, the military withdrawal was accompanied by a precipitous drop in the level of attention and engagement devoted to Iraq by senior American officials.

The decline in U.S. attention to Iraq was not only the result of the Obama administration's lack of enthusiasm for American involvement there; it was compounded by the Arab uprisings convulsing the region at the same time, which diverted the time and resources of Middle East-watchers in Washington, the desire by President Obama to shift the U.S. focus from the Middle East to Asia, and declining internationalist sentiment overall amid economic difficulties and war fatigue. Together these phenomena created a strong impression of American disengagement from the Middle East and markedly weakened the American alliance system there. The resulting security vacuum was filled not by another outside power or, as American policymakers seemed to wish, by purposeful multilateral actions, but rather by mounting disputes between regional powers, which took the form of sharply opposing approaches to Egypt, Syria, and other issues.

It cannot be known whether the presence of a residual U.S. force in Iraq, a more active U.S. policy toward the Syria conflict, or a more decisive and engaged American approach overall would have significantly changed the course of events in the region. What is certain, however, is that American and allied interests in the region are no less vital now than in the past. Indeed, the success of the American "pivot" to Asia depends in part upon Washington's success in the Middle East, because our Asian allies have strong interests in the region but depend on America's global influence and power projection (capabilities they themselves lack) to mediate disputes and ensure stability there.

Thus the United States finds itself with little choice other than to attempt to resolve the crises gripping the Middle East -- which have worsened and spread, not eased, as Washington has ignored them -- but from a weaker regional position and with weaker alliances and fewer tools at its disposal than in the past.

WHAT IS TO BE DONE

As the United States and its allies devise a response to the Iraq crisis, they will face two competing impulses. First, they will seek to avoid too deep a commitment in Iraq; for President Obama in particular, given his aversion to military engagements, this will be a priority. At the same time, they will seek to prevent the Iraq crisis, which was fed by the conflict in Syria, from spreading further, especially to vulnerable allies Jordan and Lebanon.

Just as the West's standoffish approach to both Syria and Iraq contributed to the present crisis reaching such dire proportions, reconciling these two goals will prove challenging. Three principles should guide the United States and its allies.

First, targeted military force should be used with an eye toward shaping the conditions for diplomacy. In Iraq, President Obama has made clear that a political accommodation among major factions is a prerequisite for a deeper American military commitment. However, there is little sign that a new, more inclusive government is imminent. Sunni Arab factions, long dissatisfied with Maliki, appear ready to ally with ISIS even if they do not share its ideology or ultimate objectives. Shiites, on the other hand, are apt to resort to sectarian militias as the Iraqi Army falters and outside assistance fails to materialize, which will fuel further communal violence. Disrupting this dynamic will likely require that any external intervention -- or at least its initial stage -- precede the formation of a new Iraqi government. Dealing ISIS a military setback holds the best hope of securing the political accommodation which is vital to preventing Iraq from descending further into chaos.

Second, any response should focus not only on Iraq, but on the region broadly. Defeating ISIS and preventing the spread of the Iraq crisis will require more purposeful action first and foremost in Syria, where the U.S. and its allies have done little more to date than pursue fruitless diplomatic confabs. The Obama administration has already requested $500 million to strengthen Syria's responsible opposition, suggesting that it has finally understood this need. Further assistance may also be required for Jordan and Lebanon, both of which are already contending will the spillover effects of the Syria conflict and can ill afford further strain. Finally, effective responses to any of these issues -- but particularly Iraq and Syria -- will require improved U.S. relations with its Gulf Cooperation Council allies and firmer pushback against Iranian activities in the region which contribute to instability.

Finally, the U.S. and its allies will need to combat ISIS and likeminded groups not only via military support for the Iraqi army, but comprehensively using a wide range of tools. This will mean targeting ISIS finances and logistics and working with partners to counter the organization's ideology, intercepting foreign fighters en route to and from the battlefield, and winning over the support of Sunni Arab tribes along the Iraqi-Syrian-Jordanian frontier where ISIS is most active.

CONCLUSION

While this sort of strategy does not require the massive military and financial commitments feared by Western leaders, it will require the sort of active engagement with and long-term commitment to the Middle East that they have thus far avoided. Nor is it guaranteed to succeed -- after three years of standing by as the region's crises have metastasized, the United States and its allies may find that even the best-laid plans falter, and should prepare for the possibility of Iraq's fragmentation. What responsible nations -- including the U.S. and Japan -- must avoid at all costs, however, is inaction. The absence of a policy is itself a policy, albeit one which simply ignores our important interests rather than taking the prudent steps to safeguard them that are the fundamental responsibility of policymakers.

Michael Singh is managing director of The Washington Institute.