Retired US general John Allen, the cerebral ex-commander of NATO forces in Afghanistan who also led troops in western Iraq, has been named to lead the international effort against Islamic State extremists, officials announced Friday.

The job will require a difficult balancing act that will be familiar ground to the retired four-star Marine officer, who has plenty of experience managing unwieldly coalitions and navigating the volatile politics of the Middle East.

Allen, 60, has been an unabashed hawk when it comes to Islamic State, urging a no holds-barred assault on the militants, who have employed brutal tactics in their advance across Syria and Iraq.

"The Islamic State is an entity beyond the pale of humanity and it must be eradicated. If we delay now, we will pay later," Allen wrote in Defense One last month.

As head of the NATO-led mission in Afghanistan from July 2011 to December 2013, Allen had to deal with the notoriously mercurial president Hamid Karzai -- as well as commanders from dozens of countries while overseeing the start of a troop drawdown.

And before that, as the number two at US Central Command, which oversees American forces in the Middle East, Allen devoted much of his time to tracking America's arch-foe Iran.

"In this role General Allen will help continue to build, coordinate and sustain a global coalition across the multiple lines of efforts to degrade and ultimately destroy ISIL," said State Department deputy spokeswoman Marie Harf, referring to the jihadists that have seized territory in Iraq and Syria.

President Barack Obama, in announcing a strategy to destroy the group, said the creation of an international coalition that included Arab and Muslim states was vital to the anti-IS effort.

Allen's deputy will be Brett McGurk, the deputy assistant secretary of state for Iraq and Iran.

The former commander will not oversee military operations, which is the job of the current chief of Central Command, General Lloyd Austin. But Allen likely will be asking members of an international coalition to contribute aircraft, ammunition, access to bases or other aid to the fight.

Allen is no stranger to the sectarian politics of Iraq, where he made his name from 2006-2008 in western Anbar province, forging alliances with Sunni tribes who turned on Al-Qaeda militants.

The approach to the Sunni tribal leaders was controversial at the time, and some fellow officers opposed the effort but it proved successful, producing the so-called "Anbar Awakening."

Allen, like most senior US military officers, has said Obama should have left troops in Iraq instead of withdrawing all combat forces in 2011.

Since June, Obama has deployed 1,600 troops to safeguard the US embassy and provide "advice and assistance" to Iraqi and Kurdish forces.

In late 2012 President Barack Obama nominated Allen to be supreme commander of transatlantic alliance NATO, one of the most prestigious US military posts.

But he withdrew from consideration when he was briefly caught up in the scandal that forced retired general David Petraeus to resign as CIA director due to an adulterous affair.

An inquiry was launched into alleged "flirtatious" emails between Allen and Jill Kelley, the Florida woman whose complaints about threatening emails from Petraeus' mistress brought the scandal to light.

Allen retired from the military in February 2013 and he was later cleared of any wrongdoing.

But Allen later said the publicity over the episode was excruciating for him and his family.

Since hanging up his uniform, Allen worked as an adviser to draw up a security plan for the West Bank during US Secretary of State John Kerry's failed bid to broker an Israeli-Palestinian peace deal.

A graduate with honors from the Naval Academy in 1976, Allen has pursued graduate studies throughout his career, earning masters degrees in national security and strategic intelligence.

As the head of a Marine battalion, he participated in operations handling a wave of Cuban and Haitian refugees in 1994 at the US naval base in Guantanamo Bay, Cuba before deploying to Bosnia for a NATO peacekeeping mission after the signing of the 1995 Dayton accords.

US hopes training local forces will work -- this time
Washington (AFP) Sept 12, 2014 - The United States has often struggled to turn rag-tag foreign forces into professional armies, but President Barack Obama is gambling that this time the training effort will succeed in Iraq and Syria.

Eager to avoid sending US combat troops to fight against Islamic State jihadists, Obama is touting a renewed effort to bolster Iraqi government forces and "moderate" opposition fighters in Syria with weapons and advice from seasoned American officers.

But there are doubts in Western capitals that Washington can ensure a rebuilt Iraqi army will not fall prey once again to a Shiite sectarian agenda, or overcome in-fighting and extremism among rival Syrian rebel groups.

Until now, Obama has kept the Syrian civil war -- and its confusing array of rebel factions -- at arm's length, approving only limited support for some "moderate" opposition forces.

That effort, in which a couple of thousand rebels have been reportedly trained by the CIA in Jordan, has been blasted as timid and grossly inadequate by hawks in Washington and Arab allies.

The US president vowed this week to ratchet up support for the rebels, but it remains unclear how much help Washington is ready to provide and whether the West can even identify reliable partners who could form a viable fighting force -- at a time when Islamist hardliners are ascendant.

There are hundreds of rebel groups in Syria, riven by ideological and power rivalries, manned by fighters lacking basic military skills and often dominated by Islamist radicals.

Obama has asked Congress for $500 million to train as many as 5,000 rebel fighters over the next year, using US special forces instead of CIA officers. The plan got a boost this week with Saudi Arabia offering to host the training.

But US lawmakers have been less than enthusiastic, complaining Obama has failed to explain exactly what the plan will involve.

- Islamist or opportunistic -

Senators also insist the US government must find secular-minded rebels to back, though experts who monitor the Syrian conflict say the debate in the United States is "naive."

The issue "is not being discussed at a realistic level," said Aron Lund, editor of Syria in Crisis, a report published by the US-based Carnegie Endowment for International Peace.

"Most of the insurgency is either opportunistic or Islamist to some extent," he told AFP.

The United States will likely have to demonstrate a pragmatic approach, as it has in the past in Iraq, and accept that it will have to work with rebels with an Islamist bent, according to Lund.

If Washington manages to build a small but well-trained rebel force, backed by US air strikes, it could have a significant effect in Syria, especially over time if the group scores battlefield successes.

"A small group with air support can be quite powerful," Lund said.

US officials say their first challenge is vetting recruits to ensure the program does not backfire and end up delivering weapons to anti-Western extremists or even to IS itself.

Dating back to Vietnam, US attempts to construct professional armies often have faltered, usually because the local leaders see the military as a means of holding on to power rather than defending the country, experts say.

The most recent failure occurred only a few months ago in Iraq, where a massive training effort ended with army divisions throwing down their weapons in a humiliating rout by IS militants.

The outcome, after $24 billion worth of training, came as a crushing disappointment to the US military, but most senior officers blamed the sectarian agenda of former prime minister Nuri al-Maliki, who they say appointed political hacks instead of qualified officers.

"The idea was to create an army that was reflective of the Iraqi society and that model broke down after the Iraqis took command of their own forces and the units started to become aligned in a sectarian manner," said Paul Eaton, a retired US major general who led training efforts in Iraq ten years ago.

- High hopes for new Iraqi government -

With Maliki now out of office, Washington hopes a new government in Baghdad will back an army that represents the whole country's population, including the Sunni community that became alienated under Shiite rule.

"The difference is now we have a new government, a government that has publicly proclaimed a desire to be much more inclusive and responsible," Pentagon press secretary Rear Admiral John Kirby said Thursday.

There are, however, frequent reminders of the Iraqi army's defeats.

Daily updates on the results of US air strikes in Iraq show how American aircraft are regularly blowing up Humvees and other US-made equipment, which was seized by the jihadists in the wake of the Iraqi troops' retreat.