LONDON (Reuters) - Britain's top spy, in the first public speech by a serving UK espionage chief, said on Thursday terrorists might hit the West again "at huge human cost" but nuclear proliferation by states was a more far-reaching danger.
Secret Intelligence Service (SIS) chief John Sawers, in an address to the Society of Editors media group hosted at Thomson Reuters London offices, said the risks of failure in tackling proliferation by countries like Iran "are grim."
"Terrorism is difficult enough, and despite our collective efforts, an attack may well get through. The human cost would be huge. But our country, our democratic system, will not be brought down by a typical terrorist attack," he said.
"The dangers of proliferation of nuclear weapons and chemical and biological weapons are more far-reaching. It can alter the whole balance of power in a region," said Sawers, whose century-old service is popularly known as MI6.
Sawers defended MI6's secrecy and its ties to counterparts in Muslim nations accused of poor rights records, a theme that has resurfaced in the West after the whistle-blowing Wikileaks website published secret U.S. files it said showed how coalition forces turned a blind eye to torture by Iraqi security forces.
"We are the secret frontline of our national security," he said. "Secrecy is not a dirty word. Secrecy is not there as a cover up. Secrecy plays a crucial part in keeping Britain safe."
"We have to deal with the world as it is ... We can't do our job if we work only with friendly democracies. Dangerous threats usually come from dangerous people in dangerous places."
He added that intelligence failings on Iraq before the 2003 invasion showed "politicians and officials alike" how important it was that sources of information were rigorously evaluated.
Improving intelligence performance has been a focus for the West since the September 11, 2001, attacks and the 2003 Iraq invasion, events involving profound faults in preparedness.
Former U.S. President George W. Bush launched the Iraq invasion citing a threat of weapons of mass destruction from Saddam Hussein's government. No such weapons were ever found.
On Iran, Sawers said conventional diplomacy was not an adequate means of countering its nuclear ambitions: "We need intelligence-led operations to make it more difficult for countries like Iran to develop nuclear weapons."
"STAFF RISK THEIR LIVES"
Sawers, a career diplomat, had previously been the ambassador to the United Nations, the Foreign Office's political director, and also worked as an envoy in Baghdad and as foreign affairs adviser to former Prime Minister Tony Blair.
His speech is a move to more public accountability and openness at SIS, a big cultural shift for a service that 20 years ago was so secret the government would not publicly avow its existence, even if it still enjoys more anonymity than its close U.S. ally, the Central Intelligence Agency.
The pressure on intelligence officials to be more transparent has many roots -- pressure from lawmakers to prevent abuses and improve performance, public concern over surveillance by authorities, and a need by the intelligence community to make their work known so as to widen the avenues of recruitment.
On terrorism, Sawers said al Qaeda was unlikely to achieve its goals of weakening Western power and toppling moderate Arab governments. But the threat of "Islamic terrorism" was unlikely to fade away soon and reading reports of what militants were plotting was the most draining part of his job.
"Working to tackle terrorism overseas is complex, often dangerous. Our agents and sometimes our staff risk their lives."
In a passage likely to gain attention in the Middle East, Sawers said that over time the emergence of more open and responsive government in the Islamic world would "help" counter terrorism but insisting on a sudden move in that direction might make things worse.
"TORTURE IS ABHORRENT"
"If we demand an abrupt move to the pluralism that we in the West enjoy ... the terrorists would end up with new opportunities," he said, without elaborating.
The former Bush administration often argued that terrorist organisations and their alleged state sponsors were the main opponents of democracy in the Arab world.
But Arab civil society and human rights groups say that governments friendly towards the United States are some of the most determined obstacles to democracy, repressing peaceful Islamist groups which seek power through democratic elections.
Sawers said that if SIS knew or believed its action would lead to torture taking place, it would avoid that action, even though that allowed "terrorist activity" to go ahead.
"Torture is illegal and abhorrent under any circumstances, and we have nothing whatsoever to do with it," he said.
The opening up of Britain's intelligence community gathered pace in 2006 when the then-head of the MI5 domestic security service, Eliza Manningham-Buller, appeared in public to make a speech to academics and journalists at a university campus.