Richard Dearlove says extremists are now focused on Middle East and giving them publicity in west is counter-productive

The government and media have blown the Islamist terrorism threat out of proportion, giving extremists publicity that is counter-productive, a former head of Britain's intelligence service has said.

Sir Richard Dearlove, chief of MI6 at the time of the Iraq invasion, said that Britons spreading "blood-curdling" messages on the internet should be ignored. He told an audience in London on Monday there had been a fundamental change in the nature of Islamist extremism since the Arab spring. It had created a major political problem in the Middle East but the west, including Britain, was only "marginally affected".

Unlike the threat posed by al-Qaida before and in the aftermath of the 9/11 attacks 13 years ago, the west was not the main target of the radical fundamentalism that created Isis, (the Islamic State in Iraq and the Levant), Dearlove said.

Addressing the Royal United Services Institute, the London-based security and defence thinktank, he said the conflict was "essentially one of Muslim on Muslim".

He made it clear he believed the way the British government and the media were giving the extremists the "oxygen of publicity" was counter-productive. The media were making monsters of "misguided young men, rather pathetic figures" who were getting coverage "more than their wildest dreams", said Dearlove, adding: "It is surely better to ignore them."

The former MI6 chief, now master of Pembroke College, Cambridge University, was speaking to a prepared text hours after the ITV programme Good Morning Britain broadcast an interview with a Briton who had appeared in an Isis video saying he was recruited through the internet and was prepared to die for his cause.

Abdul Raqib Amin, who was brought up in Aberdeen, appeared in an online video last month with two men from Cardiff urging western Muslims to join the fighting with Isis. He told Good Morning Britain: "I left the UK to fight for the sake of Allah, to give everything I have for the sake of Allah. One of the happiest moments in my life was when the plane took off from Gatwick airport. I was so happy, as a Muslim you cannot live in the country of kuffars [non-believers]."

Amin added: "I left the house with the intention not to go back, I'm going to stay and fight until the khilafah [rule of Islam] is established or I die."

Dearlove said he was concerned about the influence of the media on the government's security policy. It was time to take what he called a "more proportionate approach to terrorism".

MI5, MI6, and GCHQ devoted a greater share of their resources to countering Islamist fundamentalism than they did to the Soviet Union during the cold war, or to Irish terrorism that had cost the lives of more UK citizens and British soldiers than al-Qaida had done, Dearlove noted.

A massive reaction after the 9/11 attacks was inevitable, he said, but it was not inevitable the 2001 attacks would continue to "dominate our way of thinking about national security". There had been a "fundamental change" in the nature of the threat posed by Islamist extremists. Al-Qaida had largely failed to mount the kind of attacks in the US and UK it had threatened after 9/11.

It was time, he said to move away from the "distortion" of the post-9/11 mindset, make "realistic risk assessments" and think rationally about the causes of the crisis in the Middle East.

The al-Qaida franchises that had emerged since had largely "fallen back" on other Muslim countries, Dearlove said. What was happening now was a long-awaited war between Sunni and Shia Muslims that would have only a ripple effect on Britain, he suggested.

Pointing the finger at Sunni Saudi Arabia, Dearlove said the Isis surge in Iraq had to be the consequence of "sustained funding".

He made it clear he believed more attention should be paid to security threats from Europe and China, which he warned was heading inexorably into the paradox of a "strong government but weak state".