... Bush’s stumbles over whether his brother’s signature achievement in office was justified have sparked a deluge of retrospection and self-criticism from the 2016 field of GOP candidates. Sen. Rand Paul (R-KY) has taken the opportunity to promote his peculiar brand of paleo-conservative detachment from global affairs. Former Sen. Rick Santorum (R-PA) asserted that, today, “everyone accepts” that the invasion was imprudent. Senators Ted Cruz (R-TX) and Marco Rubio (R-FL) have made note of the fact that Congress would never have authorized the Iraq War if the pre-war intelligence had not mistakenly augmented Saddam Hussein’s WMD capabilities. “A dozen years later,” the Associated Press averred, “American politics has reached a rough consensus about the Iraq War: It was a mistake.”

But Republicans are wandering into a trap by attempting to assuage the journalistic establishment’s insatiable desire to see Republicans repent for the last GOP president’s nation-building exercise in Iraq. It is a fortunate accident of fate that the media has decided to review the legacy of the Iraq War and the Republican Party’s prosecution of that conflict at precisely the same moment that Middle Eastern country is coming apart. After more than nine months of U.S-led coalition airstrikes targeting the virulent Islamic State militia, the culmination of that effort has been the fall of a second great Iraqi city. Just 70 miles from Baghdad, the American servicemen and women who bled over Ramadi appear to have fought and fallen in vain.

Despite the protestations of self-satisfied scolds for whom no metric could satisfy their desire to see the American project in Iraq fail, uniting Iraq’s political and tribal leaders against Islamist insurgents in their midst was a historic victory. The West’s hard-won achievement in Iraq has been sacrificed by President Barak Obama’s eternal pursuit of the path of least resistance.

The Republican Party’s presidential aspirants now have a political opportunity that they would be careless not to exploit. For the better part of a week, the press has been reviewing the Iraq War’s legacy. As the Iraq Security Forces retreat to defensible positions around Baghdad and Iran consolidates its grip on the Iraqi capital and the nation’s Shia-dominated regions, Republicans would do well to make a compelling case for their approach to warfighting as commander-in-chief.

Contrary to all his fatuous self-pity, President Obama inherited a relatively pacified Iraq when he took the oath. His successor will not be so lucky. The 45th President of the United States will prosecute a brutal conflict against the richest terrorist organization in human history. The next commander-in-chief must convince the American public to back the prosecution of a war against an unimaginably brutish entity with an unbroken hold on territory ranging from Aleppo to the suburbs of Baghdad. The war in which the public must invest is one that is characterized by the battlefield use of chemical weapons, has become yet another proxy conflict between the region’s great Sunni and Shiite powers, and is typified by genocide and the deliberate destruction of humanity’s collective heritage.

The present spate of collective handwringing over how the events of the last decade might have been better managed is the historian’s prerogative. The United States is not electing a lecturer; the public will not make that mistake again. America will need a commander-in-chief of the armed forces who will effectively and efficiently prosecute this conflict to which the country is already committed. ...