Michael Gerson writes about taking the wrong lessons from the war in Iraq.

Whatever the eventual outcome of the Iraq War—a precipitous, politically driven withdrawal, a gradual counterinsurgency victory, or something in between—it is necessary to begin drawing some lessons. The first is unavoidable: Regime change is the most difficult of foreign policy options, the most fraught with unintended consequences, and the least suited to the American style of war. Regime removal, it turns out, is relatively easy, given our country’s unrivaled military capabilities. But regime removal is different from regime change, which may require a massive and costly effort of nation building—especially when a society has been debilitated by decades of totalitarian rule. For nearly thirty years, Saddam Hussein instilled terror and distrust, fed divisions of clan and tribe, and encouraged the fears of the Sunni minority. Wounds so deep heal slowly and gradually, and only in an atmosphere of security and order—an atmosphere the Coalition did not initially provide.

Throughout most of my White House experience, I intuitively sided with Defense Secretary Donald Rumsfeld’s combative confidence against Secretary of State Colin Powell’s caution and diplomacy. But it is now clear to me that, despite its indisputable utility on today’s battlefield, the Rumsfeld Doctrine, with its stress on light and flexible high-tech military power, is less well suited to an occupation like Iraq than are certain elements of the Powell Doctrine—especially the need for clear goals and overwhelming force. Defeating an insurgency is possible (a fact proven in Malaysia and El Salvador); and sometimes it is necessary. But this kind of counterinsurgency campaign cannot be conducted quickly or on the cheap. For years, lower-level officers had made the case that when American troops in Iraq came into an area and stayed, there was relative calm. But for years there were not enough troops to make that strategy work on a sufficient scale in Baghdad.

Another lesson concerns the power of dramatic acts of violence in a media age. Abu Musab Al-Zarqawi’s strategy in Iraq, in the end—even after his own end—was successful. Al-Qaeda was not responsible for most of the attacks in Iraq, but it authored the most spectacular and bloody ones—the destruction of mosques, the carnage at busy markets. And this had two effects. It created images of hopeless chaos in the American media, undermining public support for the war. Even more destructively, the attacks fed sectarian divisions within Iraq at the expense of democratic aspirations. The attraction of freedom is powerful. But hatred is not without its appeal, either, especially in the absence of order. A small group of ruthless men proved capable of fanning that hatred through spectacular acts of murder …

Not long before I left the White House, the president put the situation to me bluntly: “If the definition of success is no bombings on TV, America is in trouble. If the definition of success is steady progress in Iraq toward self-sufficiency, we can win.” This explains President Bush’s emphasis on public resolve. “The most important thing to know,” he continued, “is that I’m not going to waver.” Resolve is not a substitute for effectiveness and competence in the War on Terror—but effectiveness and competence cannot prevail without it …

… There is also danger in learning the wrong lessons from Iraq—or in overlearning the lessons of caution. Some claim the American project in Iraq was doomed from the beginning, because Iraqis and Arabs more broadly are culturally incapable of sustaining democracy. That is a familiar historical charge, made in other periods, against Catholics in Southern Europe, Hindus and Muslims in India, Eastern Orthodox in Eastern Europe, and Confucian cultures across Asia.