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, install a team of technocrats to run the country and weed out warlords and narco-traffickers. Those are all important priorities, but there is something else he should be doing as well: acting as a wartime leader.

So far, Karzai has been oddly disengaged from the war raging around him. Rarely if ever does he visit his own troops in the field, go to hospitals to comfort the wounded or honor the dead, as President Obama did so stirringly with his recent middle-of-the-night visit to Dover Air Force Base.

Karzai doesn't even give speeches to rally his people in the effort to defeat the Taliban. When he does speak out, it is usually to bemoan civilian casualties caused by the Western coalition, inadvertently helping to further a Taliban propaganda line. Most of the time, though, he prefers to shelter behind the high walls of his presidential compound in Kabul, where he can focus on backroom dealmaking.

That doesn't mean that Karzai is opposed to the war effort or soft on the Taliban. He must know that if the Taliban ever regains power, he would be one of the first victims dangling from a lamppost. 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 every bit as important for the future of Afghanistan as the war against the Nazis and Japanese was for the future of Britain and America. He has not been, to put it mildly, a Ramon Magsaysay — the reformist Philippine defense minister and president in the 1950s who worked closely with his American adviser, Edward Lansdale, to defeat the communist Huk insurgents.

Karzai has not even been, to take a lesser and more recent example, a Nouri al-Maliki. The Iraqi prime minister was also oddly disengaged from the war tearing his country apart when he first took over in 2006. He came into office with no military experience and with deep-seated suspicions of an army that he associated with the Baathist regime. But as he grew more comfortable in his post, he became a formidable if sometimes impetuous frontline commander.

The highlight of his tenure came in 2008, when he personally directed Iraqi troops to clear the Sadrists out of Basra and Sadr City. Those operations were not well prepared, but they proved successful with U.S. help, and as a result, they gave a tremendous boost not only to Iraq's stability but to al-Maliki's own standing. Today, al-Maliki is the most popular politician in Iraq, and his critics are fretting not that he is too weak, as they were in 2006, but that he is too strong and could run roughshod over Iraq's nascent democracy.

One factor working in al-Maliki's favor was that President George W. Bush took a close personal interest in his success. In video teleconferences and personal meetings, he served as a mentor and supporter, giving al-Maliki the kind of lessons in leadership that only one embattled head of state can impart to another.

Today, by contrast, Obama is holding Karzai at arm's length. His administration is offering ultimatums, not mentoring, to the Afghan president.

A more productive approach would be for Obama to embrace Karzai and give him some pointers while nudging him in a more reformist direction. One of the top tips he could impart would be how to act as a wartime commander in chief who rallies public opinion behind him. Problem is, Obama himself is struggling with that job — as have most of his predecessors, including Bill Clinton and Bush. That's no surprise, because there is little that can prepare anyone for that awesome responsibility. Thus Clinton stumbled over Somalia and gays in the military before finding his footing in Bosnia and Kosovo.

Bush stumbled far worse in Iraq. Early on, he was a hands-off leader, delegating the management of the war to military and civilian subordinates who failed him and the country. Bush finally matured as a leader and earned a shot at redemption in 2006, when he approved the "surge" despite Washington's conventional wisdom to the contrary. The kind of steeliness he showed in the face of adversity may even help to rescue his historical reputation from the damage done by Abu Ghraib and Hurricane Katrina.

Note that Bush is now unemployed except for the usual post-presidential activities of speech-giving and memoir-writing. Maybe it's time for Obama to summon his predecessor — as Bush himself summoned his own father and Clinton on several occasions — and ask him to undertake a special mission: Give Karzai some pointers on how to be a leader in wartime. The ultimate success or failure of our war effort could turn on whether Karzai can don that mantle as successfully as he does his trademark chapan cape and karakul hat.

Max Boot, who recently returned from a trip to Afghanistan, is a senior fellow at the Council on Foreign Relations. He wrote this commentary for the Los Angeles Times.