Hamid Karzai begins another term as Afghanistan’s president with a long to-do list. The Obama administration has made clear to him that he must crack down on corruption and weed out warlords and narco-traffickers. Those are important priorities, but there is something else he should do, too: Act as a wartime leader.

Karzai has been oddly disengaged from the war raging around him. Rarely, if ever, does he visit troops in the field, honor the dead or give speeches to rally people in the effort to defeat the Taliban.

That doesn’t mean Karzai is opposed to the war effort or soft on the Taliban. He must know that if the Taliban regains power, his days likely are numbered. But he has not embraced the war effort in the way that Franklin D. Roosevelt or Winston Churchill did — even though the war against the Taliban is as important for the future of Afghanistan as the war against the Nazis and Japanese was for Britain and America.

Karzai has not even been a Nouri al-Maliki. The Iraqi prime minister came into office in 2006 with deep-seated suspicions of the army and was oddly disengaged from the war tearing his country apart. But he grew to become a formidable frontline commander. His highlight came in 2008, when he personally directed Iraqi troops to clear the Sadrists out of Basra and Sadr City. Those operations proved successful, with U.S. help, and gave a tremendous boost to Iraq’s stability and al-Maliki’s standing.

One factor working in al-Maliki’s favor was that President George W. Bush took a close personal interest in his success. By contrast, Obama is holding Karzai at arm’s length, offering ultimatums instead of mentoring.

Bush stumbled far worse in Iraq. Early on, he was a hands-off leader, delegating management of the war to subordinates who failed him. But he earned a shot at redemption in 2006, when he approved the “surge” despite conventional wisdom to the contrary. The steeliness he showed then may help rescue his historical reputation from the damage done by Abu Ghraib and Hurricane Katrina.

Except for speech-giving and memoir-writing, Bush is now unemployed. Maybe Obama should summon his predecessor — as Bush summoned his own father and Bill Clinton on occasion — to go on a special mission: Give Karzai pointers on how to be a leader in wartime. The success or failure of our war effort could turn on whether Karzai can don that mantle successfully.

(Boot is a a senior fellow at the Council on Foreign Relations. His most recent book is “War Made New: Technology, Warfare, and the Course of History, 1500 to Today.” This essay first appeared in the Los Angeles Times.)