WASHINGTON (CNN) -- The U.S. military is seriously deficient in meeting "the threat of Islamist insurgencies," says a Pentagon-commissioned study released Monday.
A U.S. soldier patrols an anti-insurgent outpost near Jisr Majid on Saturday.
The Rand Corp. report characterizes "U.S. military intervention and occupation in the Muslim world" as "at best inadequate, at worst counter-productive, and, on the whole, infeasible." The Pentagon asked the nonprofit research organization to review strategies to thwart insurgents.
The United States should instead focus its priorities on improving "civil governance" and building "local security forces," according to the report, referring to those steps as "capabilities that have been lacking in Iraq and Afghanistan."
"Violent extremism in the Muslim world is the gravest national security threat the United States faces," said David C. Gompert, the report's lead author and a senior fellow at Rand. "Because this threat is likely to persist and could grow, it is important to understand the United States is currently not capable of adequately addressing the challenge."
The Pentagon did not respond to calls Monday from CNN seeking comment.
The report is titled "War by Other Means: Building Complete and Balanced Capabilities for Counterinsurgency."
But "it would be a profound mistake to conclude from [the troop increase] that all the United States needs is more military force to defeat Islamist insurgencies," Gompert said. "One need only contemplate the precarious condition of Pakistan to realize the limitations of U.S. military power and the peril of relying upon it."
The study notes that U.S. military interventions can be risky as well as costly because of the tenacity of jihadists, "infected by religious extremism." It says massive military interventions against insurgencies usually fail.
Looking at some 90 conflicts since World War II, the report concludes that establishing "representative, competent and honest" local government is the way to go.
"Foreign forces cannot substitute for effective local governments, and they can even weaken their legitimacy," said co-author John Gordon. The study says the United States would have more success if the insurgency were defused early and it must develop ways to interpret early "indicators and warnings."
Along with building "effective and legitimate local governments," the report says the United States must do a better job of organizing, training and equipping local security forces, and gathering and sharing information.
To beef up counterinsurgency efforts, local governments must develop "job training and placement of ex-combatants; an efficient and fair justice system, including laws, courts and prisons; and accessible mass lower education," it says.
"When it comes to building these and other civil capabilities abroad, the United States is alarmingly weak," Gompert said. "To fix this problem, the federal government will need a dramatic increase in civilian capabilities, new organizational arrangements, and more flexible personnel policies."
More money in foreign aid, more civilian professionals and help from U.S. allies and international groups are needed, the report said.
Other observations from the report include: