Can the US figure out which groups to support in Syria? Not easily.

As the US grapples with whether it should pursue a larger role in the Syrian War – and just how much military aid to give Iraqi troops battling the Islamic State – it is also trying to figure out how to avoid one of the most basic and nettlesome blunders of all: inadvertently creating a Frankenstein’s monster in the form of corrupt local power brokers.

With large influxes of cash and military training – and in ways both formal and informal – the US military has often tapped the wrong people with disastrous consequences, say senior US military and intelligence officials. 

In Afghanistan, by relying on small units of Special Operations Forces working alongside mujahideen forces, the US “super-empowered” these militias, says Lt. Gen. H.R. McMaster, widely considered to be one of the Pentagon’s premier practitioners of counterinsurgency and now the deputy commanding general of the US Army Training and Doctrine Command.

It was one of the key wrong turns in America’s war in Afghanistan. These militias in turn “morphed into organized crime networks,” he says, and eventually “hollowed out institutions that we, the international community, were trying to build.”

The lesson “is not just that these operations are impossible,” General McMaster says. “But we made this just about as hard on ourselves as we could have.”

Learning to suss out local power brokers was a complex endeavor even during the years of counterinsurgency warfare, as the American military spent a decade trying to get to know a population.

Today, counterterrorism is king, with far less time to build the network of relationships that were meant to be a hallmark of counterinsurgency. Even in a country like Afghanistan, where America has waged the longest war in its history, many of those relationships remained tenuous for years.

This point came into sharp relief this week as Afghanistan’s new president, Ashraf Ghani, visited Washington. Pentagon officials and lawmakers alike marveled at the thanks he expressed to US taxpayers and troops for their sacrifice, both financial and physical, on behalf of his country.

It was a first, press accounts noted, and a sentiment seldom if ever heard from former president Hamid Karzai, when he had turned against US involvement in his country even as he requested more funds and arms.

US officials had backed Mr. Karzai, just as they had backed former Iraqi Prime Minister Nouri al-Maliki, who US officials now concede was a corrupt and sectarian power-broker who divided the country, alienating and oppressing Sunnis as Saddam had done to the Shiites before him.

This in turn paved the way for the Islamic State’s routing of the Iraqi Army last year, as they cashed in on Sunni rage. A new prime minister, Haider al-Abadi, has promised to unite country once again.

As the US looks towards possible engagements against the Islamic State, “I think in many ways what we learn from the wars in Afghanistan and Iraq could in the future be as important as the outcomes of those wars,” McMaster adds. 

“If we learn the wrong lessons, we’ll engage in the kind of self-delusion that we engaged in in the 1990s, which will set us up for many of the difficulties that we encountered in Iraq and Afghanistan.” 

So how to avoid creating these "Frankensteins?" The US military has picked up some lessons along the way that may prove helpful in the war against the Islamic State.

Some of them are mercenary. “You have to make sure that once the fighting is over, that you establish governance that might or might not include them,” says retired Col. Peter Mansoor, the executive officer of retired Gen. David Petraeus in Iraq and now chair of military history at Ohio State University.

He points to the British in World War I, who encouraged the Arab tribes to revolt against the Turks. “For better or worse, the British did not empower the tribes they’d armed.” 

Instead, they turned the territory into colonies and sidelined the tribesman. “It’s been done in the past,” Dr. Mansoor says.

The outcome may not hold far into the future, but would still accomplish a key US foreign policy goal in the present. 

“How do you choose when you want to deal with warlords, or the equivalent of warlords? How do you choose the right ones? And how do you make them the best warlords they can be?” This was the question Robert Grenier says he wrestled with frequently, first as CIA station chief in Pakistan during the 9-11 attacks and then as the director of the CIA Counterterrorism Center.

The answer: “That’s hard,” says Mr. Grenier, who helped plan the covert campaigns that preceded the US invasion of Afghanistan. 

“The ‘pointy end of the spear’ ” – what the US military likes to call its toughest warfighting operations, often early in a conflict – ”is really, really hard,” he says.

For starters, “It takes people with a real feel for the culture, the knowledge, the languages – a real deep understanding of the history of local personalities,” he adds.

But even when all of these conditions are in place – no small feat in a US government in which language skills, even after more than a decade in region, are in short supply – it takes “great force of personality,” says Grenier, author of the new book, “88 Days in Kandahar: A CIA Diary.”

“That is very difficult to do on a wholesale basis – and that’s essentially what we’re trying to get our intelligence and military forces to do – and it is difficult under the best of circumstances.” In other words, working with warlords can easily go awry.

The result has been an “extreme wariness” about empowering the wrong people in Syria, but this approach, too, has been a mistake, Grenier argues, adding that he feels, “maybe wrongly,” that if the US had been “far more aggressive early on" in dealing with Syrian opposition groups, that “they might have been able to gain traction much earlier, and we would not have seen the space created that has now been filled by ISIS.”

This is not to say that many of even the moderate Syrian opposition forces are angels, he acknowledges. “Many of these members of the so-called moderate opposition frankly are local thugs – I mean that in the most positive way possible.”

“But if your main objective is not to make a mistake, you’re not going to get very much done,” he says. “We’ve been afraid to provide them military support lest that support ends up in the hands of a terrorist,” he notes, adding that this concern should not trump US efforts to keep trying.

But isn’t that a real and concerning risk, that US arms end up in terrorist hands? Grenier says he is willing to take that risk, that “inevitably that some of those weapons are going to end up in the wrong hands.”

The current US foreign policy in the region, after all, places a premium on empowering local actors. 

“If we want to affect the course of events from the margins as we have in the fights that are essentially not our fights – but we have a strong interest in the outcome – we’ve got to be willing to take those kinds of risks,” he says, “knowing that some of our warlord friends are going to disappoint us badly along the way.”

“The best we can do is try to influence,” he adds. “We certainly won’t have control. You want control, then you send in the 3rd Infantry Division.”

And even large military divisions are no guarantee of success. 

Gen. Benjamin Hodges recalls the early day of the Iraq War, when the arriving US forces were greeted by Shiites oppressed under Hussein’s rule “like it was 1944 in Holland,” he says. “That’s what we saw the first few days of Iraq.”

That changed in short order, however, when local power brokers began to vie for influence. As US troops tried to establish order, local operatives would step up and claim to be the senior sheikh in town.

They usually weren’t who they claimed to be, but “I didn’t know that,” General Hodges notes. “And I guessed wrong many times.”

As his career progressed, Hodges, who is now the top Army commander in Europe, grew to have great admiration for a British contemporary, Gen. Nick Carter, who negotiated the complex relationships with skill in Afghanistan, where both men also served.

“He had an unbelievable ability to understand the tribes,” to the level of detail of “the history of who was married to whose sisters,” he recalls.

“He understood the Pashtuns” – the most powerful tribe in Afghanistan – ”better than anybody I’d ever seen,” he says. “That really is the essential part.”

With the experience of the past decade, at least, comes a realization that such skills are important, US military officials add. 

Time is no small factor, argues Ohio State’s Mansoor. “It’s very difficult, and it requires us to remain on the ground in some capacity. This idea that we want to fight and get out works against us creating something stable.”

McMaster, for his part, calls this “the George Costanza approach to war,” a reference to a character on the TV show "Seinfeld" obsessed with leaving on a high note.

“War is a contest of wills,” he says. “We have to learn lessons from that.” 

In World War II and, after that, Korea, US troops learned that “you have to stay,” Mansoor adds. 

Now, there is little political appetite for that, but perhaps civilian leaders could generate such support with a frank national conversation, McMaster says. 

And in an era when troops are increasingly speaking out about the alienation they feel from the civilians they protect, it might, at the least, inspire some understanding of the challenges the US military faces, officials say. 

“How many Americans can name the three Taliban groups?” McMaster notes. “Can you imagine fighting a war in the past and not even being able to name the enemy?”