General Stanley A. McChrystal (R) sits in the helicopter after a lengthy conference meeting with military officials October 7, 2009 at the forward operating base (FOB) Walton, outside of Kandahar, Afghanistan. (Paula Bronstein/GETTY IMAGES)

Robert H. Scales, a retired Army major general, is a former commandant of the U.S. Army War College.

President Obama may be developing a strategy to confront the apocalyptic horrors of the Islamic State, but he already has a method, a gift of sorts from soldiers who have been fighting similar enemies for more than a decade.

To understand, consider some history: George S. Patton’s method of war, the one that defeated the Wehrmacht in the European theater in World War II, consisted of a mechanized war doctrine stolen from the Germans, plus a uniquely American skill for applying air- and land-delivered firepower in support of tanks on the move. Patton’s method would be perfected during future U.S. and Israeli conflicts, culminating in the “Great Wheel” envelopment of Saddam Hussein’s army in Desert Storm in 1991 and the march to Baghdad in 2003.

Over time, however, enemies learn and adapt. Eventually, Patton’s method was successfully challenged in Lebanon, by Hezbollah’s anti-tank missiles, and in Iraq, by al-Qaeda’s improvised explosive devices.

Enter a new prophet, Gen. Stanley McChrystal, the former head of the U.S. Special Operations Command. Over the past 20 years, McChrystal and his teams have developed another uniquely American method of war by substituting skill, information and precision for mass, maneuver and weight of shell. We first watched the McChrystal method at work in Afghanistan following the attacks of Sept. 11, 2001, when small Special Forces units and the Afghan Northern Alliance teamed to destroy the Taliban using precision strikes delivered from aircraft high overhead.

But the secret of this new method is in people, not technology. McChrystal’s success proves that small units of superbly selected, trained, educated, led and bonded soldiers can kill much larger aggregations of enemy while holding the deaths of friendly forces and innocent civilians to a minimum.

Make no mistake, the McChrystal method is about killing, but it is killing of a different sort. The president has lamented the “whack-a-mole” nature of battling insurgents and militants. But whack-a-mole tactics work when the moles are enemies who occupy critical positions within terrorist networks, when they are essentially a middle-management layer of leaders, communicators, transporters, financiers, technicians and enforcers.

In many ways, the McChrystal method is the opposite of shock and awe. It is often painfully deliberate, fed as it is by the patient collection of intelligence wrung from sources as disparate as informants and the big ears of the National Security Agency. Nothing happens without repetitive, realistic planning and rehearsals. No operation goes down without involving many layers of “enablers.” Intelligence officers feed information constantly to teams as they move to the fight. Armed and unarmed drones feed video of enemy movements. Some of the killing is done up close, to be sure, but most comes from precision aerial weapons that obliterate the enemy in the dead of night.

The day will inevitably come when the McChrystal method is employed against the Islamic State. But crushing the group will require a scaling-up of the method, never attempted before. The Islamic State is huge, and, sadly, the men and machines necessary to do the job are too few and have been terribly overused. To succeed, the McChrystal method will have to be cloned to a degree as yet unimagined within the Defense Department.

Obstacles to this are many. The Special Operations Command could be the most intractable enemy of replicating the approach. It argues that such elite forces can be made only in small batches. Truth is, there are more than enough men to fully expand the McChrystal method if some Army and Marine close-combat forces were repurposed. Of course, such a transformation would take time. Building a conventional “elite” force would require a ruthless culling of the ranks to allow only the best and brightest to be selected, trained and bonded together in a manner proven by decades of success in the special operations community.

There are equipment issues as well. The Special Operations Command makes its own materiel — and its stuff is much better than what is carried by conventional forces. A means must be found to transfer and proliferate the superior weapons, sensors, radios, body armor, helicopters and vehicles to these newly created “conventional” special operators.

Drones are the modern equivalent of Patton’s tanks, and we simply have too few. The shortage is due in large part to the reluctance of the air services to embrace the need for unmanned, “unblinking eyes” positioned permanently over any ground forces in harm’s way. The Air Force and Navy must be made to expand their fleets of drones tenfold or more.

The Islamic State cannot be defeated by diplomacy, sanctions, coalitions or political maneuverings. Its fighters must eventually be killed in large numbers, and Americans will never allow large conventional military forces to take them on. The butcher’s bill would simply be too large. The only sure means for defeating the group is with a renewed, expanded and overwhelming legion of capable special fighters who have learned through painful trial and error how to do the job.