Former CIA director and retired four-star general David Petraeus says the foremost threat to Iraq's long-term stability is not the Islamic State, but Shia militias backed by Iran. File photo by Jim Ruymen/UPI | License Photo

WASHINGTON, March 21 (UPI) -- Gen. David H. Petraeus, former ground commander of U.S. troops in Iraq, said the biggest threat to Iraq's long-term stability is not the Islamic State, but Shia militias backed by Iran.

In an interview with the Washington Post, Petraeus said Iraq and its allies are making "considerable progress against the Islamic State," and that while Shia militias helped protect Baghdad from advancing IS forces, they have also committed atrocities against Sunni civilians.


"Thus, they have, to a degree, been both part of Iraq's salvation but also the most serious threat to the all-important effort of once again getting the Sunni Arab population in Iraq to feel that it has a stake in the success of Iraq rather than a stake in its failure," Petraeus said. "Longer term, Iranian-backed Shia militia could emerge as the preeminent power in the country, one that is outside the control of the government and instead answerable to Tehran."

Iranian influence on Iraq's Shia militias goes back to the U.S. occupation, when Tehran supplied sophisticated roadside bombs known as "explosively-formed penetrators," or EFPs, to combat U.S. troops.

Since the IS blitz across Iraq last year, Iran's military has provided assistance to its embattled neighbor. A general with Iran's Revolutionary Guards was killed by a sniper while training Iraqi security forces and Shia militants in Samarra, Iraq, late last year.

Tehran has scoffed, however, at cooperation with the U.S.-led coalition against the Sunni extremists.

In September 2014, Iranian commanders threatened to attack deep into Iraqi territory if IS militants came too close to Iran's western border, but Iranian forces that had been built up in the region were largely removed last month after advances by IS forces were halted within Iraq.

Tensions over Iran have increased amid negotiations with the West over its nuclear program. The Obama administration and allies have leveraged a drop in economic sanctions in return for limitations on Iran's nuclear capability.

Newly re-elected Israeli Prime Minister Benjamin Netanyahu condemned the negotiations as "shortsighted" and a "bad deal" during a speech to the U.S. Congress earlier this month.

Iran has repeatedly called for Israel's destruction, and while it claims its program is for energy purposes, the U.S. and Israel suspect it could be militarized.

"This deal won't change Iran for the better. It will only change the Middle East for the worse," Netanyahu said, adding that the days are over when the "Jewish people remain passive in the face of a genocidal regime."

President Barack Obama contends the talks could "help open the door to a brighter future."

"I believe that our nations have a historic opportunity to resolve this issue peacefully -- an opportunity we should not miss," Obama said in a recent message sent to Iranians to mark the Persian new year.

Meanwhile, Saudi Arabia surpassed India as the world's top arms importer earlier this month, spending $6.5 billion on defense imports in 2014 -- a 54 percent increase from 2013 levels. The Sunni kingdom is seen as the region's traditional counterweight to Shia Iran.

"It may be a way of tempering that rapprochement with Iran," David Cortright, director of policy studies at the University of Notre Dame's Kroc Institute for International Peace Studies, told i24 News. "You can think of it as ... deepening ties in a time of uncertainty, as a possibly greater role with Iran looms on the horizon."