With Lt. Gen. Stanley McChrystal taking over as the top U.S. commander in Afghanistan, the war there now will be led by a former head of the Joint Special Operations Command, a master of the kind of covert operations and counterinsurgency tactics that have become decisive in this age of asymmetric warfare.

McChrystal succeeds Gen. David McKiernan, who was forced out after less than a year in the post. Defense Secretary Robert Gates said McKiernan had served with honor, but "a new approach was probably in our best interest."

Military analysts and veterans who have worked with McChrystal describe him as a detail-oriented officer who remains flexible in response to changing conditions on the ground -- traits that should serve the West Point graduate well in the loosely defined, constantly shifting Afghan theatre in which he now will call the shots.

"I actually briefed him at least three times," recalled U.S. Army Lt. Col. Anthony Shaffer, a former Army intelligence officer who served two tours in Afghanistan and now is attached as a reservist to the Center for Advanced Defense Studies in Washington. 

Shaffer recalled working directly with McChrystal in support of Joint Task Force 121, an elite special-ops unit that excels in the capturing and killing of high-value enemy targets.

In that specialized realm, both men boast extraordinary experience: Units under McChrystal's command were credited with capturing Saddam Hussein and with killing Abu Musab al-Zarqawi, the head of Al Qaeda in Iraq. And the records supporting Shaffer's Bronze Star, awarded to the Ohio native in 2004, state that "his actions contributed to [the] killing or capturing of more than 100 Taliban fighters."

"The press talks about [McChrystal] being adaptive, being able to adjust and make decisions which are practical," Shaffer said."And I saw that firsthand, where he was able to make an adjustment which he didn't want to make. But we were able to go in with the facts and lay out to him the issues, and he begrudgingly made the change. And by making the change, he allowed us to be successful. So I think he's a very pragmatic commander, from my experience."

Many analysts have argued for the U.S. military presence in Afghanistan to carry a lighter footprint. In particular, Afghan officials have complained about bombing campaigns that have been conducted or supported by the U.S. and which have resulted in heavy civilian casualties.

The latest such incident to roil Afghans was an attack in Farah province last week that left close to 150 people dead. Although the casualties were initially blamed on U.S. warplanes, McKiernan said last week that the U.S. possessed "other information that leads us to distinctively different conclusions about the cause of those civilian casualties." 

Since his ouster, the Washington Times reports, aides to McKiernan have even suggested that the Taliban forced civilians to shoot at U.S. and Afghan forces and thereby incur the fire that killed the non-combatants.

As a specialist in covert operations and counterinsurgency tactics, McChrystal is expected to deliver the "lighter" footprint the U.S. needs in Afghanistan and also to do a better job of integrating the work of soldiers with that of diplomats, aid workers and others whose efforts are essential to choking off local support for the Taliban. 

"General McChrystal brings that precision and the understanding of all the facets of what needs to be controlled and influenced on the ground," Shaffer said. "He, I believe, will be successful in translating broad policy guidelines into achievable, measurable objectives regarding military activities -- which will result in, frankly, a regaining of lost ground in Afghanistan."

Former Vice President Dick Cheney agreed. In an interview with FOX News' Neil Cavuto, Cheney called McChrystal "an absolutely outstanding officer."

"I'm not saying anything critical of General McKiernan, who's leaving," Cheney said. "But Stan McChrystal was head of the Joint Special Operations Command. ... I think the choice is excellent, and you'd be hard put to find anybody better than Stan McChrystal to take on that assignment."

On Capitol Hill, the top Obama administration official on Afghanistan and Pakistan policy, Special Representative Richard Holbrooke, took note of the Pentagon's personnel change and predicted it would reverberate beyond Afghanistan's borders.

 "As you know, there's been a very important command change in Afghanistan yesterday," Holbrooke told the Senate Foreign Relations Committee. "That doesn't apply directly to Pakistan, but anything that happens in one country affects the other."