Anglo-American air strikes on Islamic State positions in northern Iraq could "increase the risk" from homegrown terrorists in the West, the former head of counterterrorism at MI6 has warned.
Richard Barrett, who handled counterterrorism operations for Britain's Secret Intelligence Service both before and after the 9/11 attacks, told the Huffington Post UK that the latest military intervention by the West "does rather play to the [jihadist] narrative that these bad regimes are being supported by outside powers and, therefore, if you get too close to overthrowing them, the outside powers will come and beat you up."
The people who were "going to fight [Bashar Al] Assad or [former Iraqi prime minister Nouri Al] Maliki are now seeing a broader enemy" in the form of the US and UK governments.
"The argument that they could also achieve the same [result] by [conducting] terrorist attacks in Western countries becomes stronger [though] not necessarily inevitable."
Such critical comments from one of the West's leading experts on Al Qaeda and its affiliates will come as a blow to President Barack Obama and Prime Minister David Cameron as the two leaders continue to authorise military action against Islamist militants in the north of Iraq.
Writing in the Sunday Telegraph at the weekend, Cameron claimed that "if we do not act to stem the onslaught of this exceptionally dangerous terrorist movement, it will only grow stronger until it can target us on the streets of Britain."
Barrett, however, warned that taking military action could, inadvertently, exacerbate the threat to people living in the West. "If ISIS pull back from Mosul, as a result of air strikes, they're not going to disappear, they'll still be out there," he said, pointing out that fighters from the UK and other European countries would return home and be much more motivated to attack targets in the West.
"Their justification will be: 'If it hadn't been for air strikes we would be fine, establishing our caliphate [in Iraq].. Why did you mess with us? Now we'll mess with you.'"
Barrett, who has also served as coordinator of the UN's Al-Qaida/Taliban Monitoring Team and is currently a fellow at the Royal United Services Institute (RUSI) in London, pointed to the situation in Libya where "military intervention without a proper plan to follow up had all sorts of unintended consequences and led to chaos and instability".
He also noted how Cameron has conceded that the struggle against Islamic State and other jihadist groups is ultimately a fight within the Muslim-majority world, between moderates and extremists, but asked: "If that's the case then what are we doing there? Where are the Saudi aircraft? There's a disconnect between what [Cameron's] saying and what's he's doing."
Both Cameron and Obama have publicly pledged that they won't be putting 'boots on the ground' but the former MI6 counterterrorism chief believes the UK and US governments could be on a slippery slope in northern Iraq.
"You start with some air strikes then you have a few more, then we need people down there to tell us where targets are [so] we put special forces in, then they're in a pickle and they need force protection, before you know it, we're drawn down this road that has no obvious ending," he told HuffPost UK.
Military action, said Barrett, should always be a last resort and isn't the "tool that is going to solve the [Islamic State] problem. Look at Libya, look at Afghanistan, look at Iraq in 2003. It's just reaching for a hammer because it is a hammer and it's to hand."
Diplomatic efforts aimed at getting Iran and Saudi Arabia around the negotiating table to resolve their differences and form a united front against groups such as Islamic State are "going to have much more impact [on Iraq] than flying out [aircraft] and dropping bombs - or even food parcels. We have to be careful that people aren't interpreting [air strikes] as gesture politics". Such strikes, Barrett argued, "have to have a very clear purpose and objective" but "I'm not sure we have that".
On Sunday, the Church of England attacked the government for having no "coherent or comprehensive approach" to tackling the rise of Islamist extremism across the Middle East. Labour has said the government's position on military action in Iraq is "pretty unclear".
Asked how he would 'defeat' Islamic State, Barrett told HuffPost UK that the key "was drawing down any sort of public support or community sympathy [for the jihadists].. Sure, then you can attack [Islamic State's] support base, the oil fields [and] stop foreign fighters going to join them as well. But you have to ask why [the foreign fighters] are doing it? How can we understand why they're doing it?"
Security services in the UK estimate that around 500 young Muslim men from the UK have gone out to fight with jihadist groups in Syria and Iraq in recent months.
Barrett believes it is politics, not religion, that is driving the radicalisation process. "I don't think the 400 or 500 people who have gone from Britain have been brainwashed in madressas; what they're doing is being pushed [and] pulled... The push factors [include] some sort of alienation, disaffection and a lack of identity, of a real sense of purpose... Pull factors are a [Sunni] community [in Iraq and Syria] that is vulnerable and that is being discriminated against and a brave band of warriors that's trying to defend them."
On the positive side, however, the latter argument is "becoming weaker because everyone knows what ISIS and Jabhat al-Nusra represent," he explained.
The former UN terrorism expert praised counter-extremism plans drawn up by the Home Office in recent months but added that British Muslim communities "need to feel confident about working with the authorities and reaching out for help [against extremism]."