The former head of MI5, Lady Eliza Manningham-Buller, has delivered an impassioned defence of talking to terrorists, even to elements of al-Qaida.
"Dialogue, even with terrorists, is necessary", she told an invited audience at the recording of her third and final BBC Reith lecture, on the theme Securing Freedom, in the British Library in central London.
"Talking doesn't mean approval", she said. "It's a way of exploring peaceful options, what compromises, if any, can be reached". She added it required courage by governments. She continued: "Not all terrorist are evil, though their acts are". There were people in al-Qaida who were tired of terror and already prepared to help the west. She said she was not suggesting "rushing off to do it tomorrow" but to consider which "components" of al-Qaida western interests could speak to.
She has already provoked some of her former political masters in Tony Blair's government by attacking the invasion of Iraq and decrying the term "war on terror", in her earlier Reith lectures.
On Monday, she went further, saying it was important "to try and reduce terrorism by talking to its advocates". It was important, she said, to keep a "rational perspective" about the risks of terrorism.
Politicians "lose their way" if they become too apprehensive about how the media would respond to terrorist attacks, she said. Attacking the many anti-terrorist laws passed by the Labour government, she spoke of "unnecessary" and "unproductive" measures. "The rush to legislation after an atrocity is often a mistake."
British governments, she said, had talked to the Provisional IRA in Northern Ireland. She said she would not exclude talking now to dissident Republican groups there. Asked after her lecture whether the west should talk to Hamas, the militant group governing Gaza, she replied: "I believe talks are going on. I'm not going to say more than that".
She described the use of intelligence agencies in "deniable" operations as "quite useful". MI6 carried out back-channel talks with the IRA under the Thatcher government though it is unclear exactly what ministers knew about them.
It is also unclear what ministers knew about MI6 involvement in "rendering" Libyan dissidents and terror suspects to Muammar Gaddafi's security forces in 2003.
There is a question, Manningham-Buller, who was head of MI5 at the time, said "whether the UK supped with a sufficiently long spoon". She made it clear in an earlier Reith lecture that, in her view, the activities of MI6 were wrong.
She is expected to give evidence to the Gibson inquiry into allegations of British collusion in the torture and the abuse of detainees.
Her lecture, the third on the theme, Securing Freedom, will be broadcast on BBC Radio 4 on 20 September.