BEIRUT

The Nazi response to the humiliation laid against the Germans at Versailles in 1919 has taught us one indelible lesson: rarely has a defeated party in warfare incurred significant punitive measures and not sought retribution.

Such is the case with the Sunnis of Iraq. Without acknowledging the mistreatment of Sunnis after the U.S. invasion of Iraq in 2003, it's impossible to understand the rapid success of the Islamic State of Iraq and Syria (ISIS), the bitter divisions between Sunnis and Shias, and the role of the U.S. occupation in increasing the likelihood of sectarian conflict.

Neoconservative ideologues have taken to the airwaves to distance themselves from the consequences of their decisions in Iraq. They have reduced recent events in the Middle East to primordial sectarian conflict or have shifted the blame to President Obama's decision to withdraw American troops prematurely. This narrative fails to acknowledge the deeper roots of the current crisis: the persistent ethnic cleansing of Sunnis that has taken place over the past 11 years, a campaign in which U.S. military power has played a central role. The story of ethnic cleansing began in 2003 with measures taken by American envoy Paul Bremer. Shortly after deposing the Saddam Hus sein regime, Bremer decided by fiat to eviscerate Sunni political, economic and military power in Iraq. In a campaign of de-Ba'athification, Bremer cleansed the Iraqi military of members of Sad dam's predominately Sunni political party, the Ba'athists.

But the U.S. did not stop with the military. Driven by free market fanaticism, Bre mer resided over the complete destruction of the Iraqi state. The U.S. laid off roughly 500,000 state workers and sold off state assets to western investors in what was perhaps the greatest looting of a foreign country in modern times. Saddam's regime was not exclusively Sunni, and enormous diversity and divisions exist within the Sunni community in Iraq. So it may be simplistic to argue that the dismantling of Baathist power targeted the Sunni community exclusively, but Sunnis perceived it as such.

This left a large population of unemployed, well-trained Sunnis rightly fearful of an emerging Shia hegemonic political order.

Over the following six years, the Bush administration did little to assuage Sunni fears of marginalization. On the heels of two vicious U.S. incursions into Fallujah in 2004 and 2005 that devastated the Sunni community in Anbar pro vince, the Bush administration pressed for parliamentary elections. The Sunnis boycotted these elections, largely in response to the atrocities that had occurred in Fallujah. The result was a Shia- and Kurdish- dominated parliament, and since then the Sunnis have struggled to mount any political resistance to the new political order.

If the 2007 troop surge did indeed achieve American military objectives -- a tenuous claim at best -- it worked in a way that further marginalized Sunnis and segregated Sunni and Shia communities. Fur thermore, it helped to consolidate Shia power in Baghdad. Sunnis constituted roughly 40 percent of Baghdad's population in 2003; by the end of the surge, it was closer to 10-15 percent.

What this amounts to is an ethnic cleansing of the Sunni population, started by U.S. policy, continued by Shia militias, and consolidated in the political arena by Prime Min is ter Nouri al-Maliki. It is no wonder, then, that ISIS has moved so swiftly through the predominately Sunni cities of Iraq. This is by no measure an indication of ISIS's popularity in these areas, but rather an expression of the population's resistance to the brutal and sectarian policies of Maliki's regime. 500,000 people fled Mosul last week not necessarily out of fear of ISIS, but in anticipation of a response from Baghdad -- or, worse yet, the U.S.

None of this is to deny that sectarian divisions existed before the U.S. invasion, or that these cleavages would have continued to shape a post-Saddam Iraq with or without U.S. intervention. But U.S. policy has ensured that any conflict between Sunnis and Shias would be violent and radicalized.

Insisting that the U.S.-led invasion and failed state-building campaign did not play a significant, if not the primary role, in precipitating the current crisis is tantamount to saying the Versailles Treaty and the humiliation of the Second Reich played an insignificant role in bringing on WW II. If the neoconservatives had heeded the lessons of WW I, it would have thought twice about systematically disenfranchising the Sunnis of Iraq. Then again, awareness of and sensitivity to the lessons of history seems like an unreasonable standard for an administration that brought us to Iraq in the first place.

A graduate of Taconic High School, Tim Eddy is pursuing an MA in Political Science at the American University of Beirut.