Friday, May 14, 1999 Published at 19:03 GMT 20:03 UK
Who's being spied on?
New claims that Chinese agents have penetrated a top level US nuclear weapons laboratory are a sobering reminder that the art of spying is still alive and well.
The Cold War may be over, but as the case of the former MI6 spy Richard Tomlinson shows, there is still plenty of cut and thrust in the covert world of state intelligence.
Of course things have changed dramatically since the era of Burgess and McLean. Britain's two main security services, MI5 (domestic operations) and MI6 (overseas), like the CIA in America, have suffered budget cuts and problems with staff morale.
And recruitment is no longer down to the simple "old school tie" principle, but instead conducted through newspaper advertisements and telephone inquiry lines.
Added to this is the fact that it is now more difficult than ever to "know your enemy". The days of the monolithic enemy - Soviet communism - are long gone.
But something that has not altered, at least according to the chairman of the Parliamentary Intelligence and Security Committee, Tom King MP, is the work level.
Earlier this year, Mr King sought to justify the role of security services in this post-Berlin Wall age, and the £700m annual funding they receive.
"This is a more complicated world. The threats are changing. They are no less but are not the same nature," he said.
"The business of spying is still very active. It's still a very important aspect of the security of every large and most middle-sized powers, as well as smaller countries that are in a threatening situation."
One of the most high-profile targets of intelligence services is terrorism.
Despite the peace process in Northern Ireland, terrorism is still viewed as a major threat in the UK's corridors of power. Stella Rimington, before she finished as head of MI5, said it took up about 50% of the agency's time.
The bombings of US embassies in Nairobi and Dar es Salaam last August, raised the stakes in the war against international terrorism.
Blame for the attacks was pinned on the Islamic fundamentalist Osama bin Laden and America's subsequent missile strikes on targets in Sudan and Afghanistan were, it is claimed, the result of its international intelligence operations.
Organised crime, traditionally targeted by regular police, was added to the remit of the UK's security services in 1995/6. It encompasses the fight against drug trafficking, arms shipments and money-laundering.
The decision to add it to the portfolios of MI5 and MI6, or "five" and "six" as they are known in the trade, led to concerns they were becoming overloaded with work.
Involvement in espionage and counter-espionage is largely a "continuation of the traditional role, in so far as we still have states against us," says Prof Wilkinson.
On the surface, relations between the UK and Russia may be better than at anytime during the Cold War, but scratch deeper and there is still great uncertainty.
"While Russia may be a friendly face at the moment, there are uncertainties about it in the long-term. Will groups that are very anti-Western in the Russian Duma push the present, moderate leadership and form a leadership that is much more hostile?"
Industrial and economic espionage has witnessed huge growth as technology has become more powerful and accessible. It is the job of security operatives to keep track of equipment which might fall into the "wrong hands".
Another aspect is that seemingly benign technologies may have a dual use and so be used for military purposes.
This spills over into the fight by Western governments to stop the spread of nuclear and chemical weapons - counter-proliferation.
"We live in an age where a number of regimes are trying to equip themselves with nuclear or chemical weapons - weapons of mass destruction," said Prof Wilkinson.
Keeping track is somewhat harder, as can be seen in the case of India's first nuclear test, last year, which caught the rest of the world completely by surprise.
Yet Prof Wilkinson says that while intelligence services often take the rap, mistake may be the fault of governments which chose not to act of information.
And he remains convinced of the need for secret intelligence.
"The value of intelligence in times of crises is so great that whatever blunders you find you still cannot come to the conclusion that says a democratic premier could do away with them."