Britain may have to use its military prowess to tackle the threat posed by the "poisonous" brand of Islamic extremism in Iraq that could bring terror to the UK, Prime Minister David Cameron warned today as he described the fight against jihadists a "generational struggle".
"True security will only be achieved if we use all our resources – aid, diplomacy, our military prowess – to help bring about a more stable world. 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," Cameron wrote in 'The Sunday Telegraph'.
In his article, he said that "humanitarian response" to the Islamic State (IS) was not enough.
"We need a firm security response, whether that is military action to go after the terrorists, international cooperation on intelligence and counter-terrorism or uncompromising action against terrorists at home," he said.
"I believe we will be fighting this generational struggle for the rest of my political lifetime," Cameron said.
"We face in Isil (IS) a new threat that is single-minded, determined and unflinching in pursuit of its objectives," Cameron wrote.
IS has seized large parts of northern Iraq and Syria over the summer. Kurdish forces, supported by US air strikes, are battling to retake Mosul dam from IS fighters in northern Iraq.
There are also continuing reports of massacres of non-Muslims by the extreme Sunni group, which is seeking to build a new Islamic state spanning Iraq and Syria.
Whole communities of Yazidis and Christians have been forced to flee in the north, along with Shia Iraqis, whom IS do not regard as true Muslims.
Cameron made clear that he did not see this as a "war on terror" but as "a battle between Islam on the one hand and extremists who want to abuse Islam on the other".
Warning that Islamic State fighters already control thousands of square miles of territory, he says that if these "warped and barbaric" extremists are not dealt with now, they will create a "terrorist state" on the shores of the Mediterranean.
"The creation of an extremist caliphate in the heart of Iraq and extending into Syria is not a problem miles away from home. Nor is it a problem that should be defined by a war 10 years ago. It is our concern here and now," he said.
"Because 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. We already know that it has the murderous intent."
His strong views came as Church leaders across the UK expressed concern that Britain had no "coherent" approach to tackling Islamic extremism.
The Bishop of Leeds warned "many" senior clergy in the Church of England were seriously concerned about Britain's approach to the handling of the Iraq crisis.
The Right Rev Nicholas Baines has written to Cameron asking about the government's overall strategy in response to the humanitarian situation and to IS.
"Behind this question is the serious concern that we do not seem to have a coherent or comprehensive approach to Islamist extremism as it is developing across the globe," he wrote, in a letter published on his website.