The Pentagon is for the first time requiring private security contractors to meet a series of certifiable standards that govern how their businesses are run and how they operate overseas, a move that some say is long overdue.

Sparked in part by the fatal shooting of 14 unarmed Iraqis in 2007 by Blackwater Worldwide guards, the effort gives the Pentagon the ability to more easily hold accountable companies that go rogue and is designed to improve the performance and image of an industry often seen as run by mercenaries.

In future contracts, the Pentagon will require companies to meet dozens of standards including thoroughly vetting and training employees, safeguarding weapons and ammunition, abiding by local laws, protecting human rights, and outlining rules for use of force.

Because the standards will become part of the contracts, the Defense Department then has recourse if things go wrong, officials said.

If there is an incident, “you can take action immediately and notify the company you’re canceling the contract,” Deputy Assistant Defense Secretary Gary Motsek said in an interview. Contracting officers “have the tools and standards to measure against, so there’s a better level of positive control than we’ve ever had before.”

But Christopher Shays (R), the former Connecticut congressman who was the co-chair of the Commission on Wartime Contracting, said that the ability to hold private contractors to account should have been put in place far earlier.

“It’s just sad that it takes so long to do the obvious,” he said. “It’s taken far too long, embarrassingly long. . . . Candidly, it’s just one more kind of example where people begin to lack faith in their government.”

Another problem, officials said, is that while the Pentagon has adopted the standards, the State Department has not. That is troubling, they said, given that the State Department relies on private security contractors in large numbers and was the agency Blackwater was working for at the time of the shooting in Iraq.

In a statement, the State Department said Congress required that the standards apply only to the Pentagon. But the State Department “is looking at incorporating them into its future security contract opportunities,” including when it awards a major contract next year to protect diplomatic personnel around the world.

Motsek and others said that developing the standards was a massive and time-consuming undertaking that involved more than 200 people from 24 countries, with representatives of governments around the world, the industry and human rights organizations.

Given the complexity of the effort, it was completed quickly, they said.

Concerns about how private contractors were operating overseas spiked during the wars in Iraq and Afghanistan. In 2004, four Americans working in Iraq for a security contractor were killed, and two of their burned bodies were hung from a bridge in Fallujah. In 2007, the Blackwater shooting in Nisour Square again drew attention to the roles that contractors were playing in the wars. And last month, a federal jury in Washington convicted four guards in the shooting — one of the darkest chapters of the Iraq war.

At one point, there were as many as 50 private security companies with more than 30,000 employees working in Iraq, providing security and intelligence services.

Congress ordered the Pentagon in 2011 to come up with a set of standards that could be audited and made part of the contracting process. The initiative grew out of earlier efforts designed to raise the professionalism of the industry — such as the Montreux document and the International Code of Conduct, which has hundreds of companies across the world as signatories.

While those efforts have been criticized as toothless, the association overseeing the international code is working to increase oversight and accountability.

But the Pentagon said contractors can now be audited to ensure they are in compliance with its standards. And some contractors are starting to get certifications from independent third parties to show that they meet the standards.

“There was recognition that okay, great, we’ve identified best practices for states. What about the companies themselves?” said Rebecca DeWinter-Schmitt, co-director­ of the Human Rights in Business Program at American University Washington College of Law, who helped craft the standards. “While there were industry codes in existence, there was nothing with real teeth to it out there.”

Companies, particularly the more reputable ones, were eager for the standards because they will raise the quality of the entire industry, said Marc Siegel, commissioner of the Global Standards Initiative at ASIS International, the group that developed the standards.

“The good companies want the bottom feeders out of the market,” he said. “Bottom feeders can always underbid, and if one of them screws up, it casts a bad light on everybody else. . . . The companies that really want to do this as a serious business want to be seen as doing it seriously.”

One of the first companies to be certified by an accredited body is GardaWorld, a Canadian firm that is the largest privately owned security company in the world.

The company said it is “wholly committed to the application of effective standards to this industry” because it “will significantly reduce the likelihood and the impact of negative or disruptive incidents, and will support a safer workplace, even in high risk environments.”

There is a benefit for the government agencies and companies that hire security contractors as well, officials said.

“It will minimize the likelihood of something going wrong,” Siegel said. “And it will also give them some protection because they can say, ‘We really did try to do this the right way.’ ”