More than a decade after the end of the Cold War, spies are back in the news.
Modern spies are not thought to be the shadowy figures of the past
But instead of hardened KGB agents lurking on street corners in dark glasses, the spy stories appearing in the Western press recently have been about fresh-faced Chinese students.
Some are said to be engaged in research at respected foreign establishments, while others are enrolled as bright young business trainees in major Western companies.
Their mission - or so the reports allege - is to use fair means or foul to gather technological and commercial intelligence that will help speed China on its way to becoming the next global superpower.
Britain's Sunday Telegraph reported recently that a leading Chinese agent had "defected" in Belgium and blown the whistle on hundreds of Chinese spies working at various levels of European industry.
The Belgian-based economic espionage network used a group called The Chinese Students' and Scholars' Association of Leuven as a front organisation, according to the French newspaper Le Monde.
These allegations follow the case of a 22-year-old Chinese woman who was detained in France after being accused of "illegal database intrusion" by the car-parts maker Valeo, which had employed her as an intern. She has since been released.
Police in Sweden also suspect Chinese guest researchers of stealing unpublished and unpatented research from an institute there, according to the Swedish radio Ekot's website.
Chen Yonglin, a Chinese diplomat who recently defected in Australia, claimed Beijing had as many as 1,000 spies in Australia alone.
But Mr Chen, a former first secretary at the Chinese consulate-general in Sydney, told the BBC News website that his lawyers had told him to say no more, for fear of jeopardising his chances of receiving political asylum.
The cool response to Mr Chen's and other defectors' requests says much about current Western attitudes towards China.
Whether in government, business or academic circles, there is a general reluctance to do or say anything that might unduly upset Beijing and threaten access to its markets - not to mention its vast pool of high-paying and often highly gifted students.
China has sent 600,000 students overseas in the past 25 years as part of a conscious policy of developing its science, technology and business skills.
Li-Li Whuang was accused of "database intrusion" in France
While some belong to well-off families who simply want their children to get a good education, most are funded by the government and are expected to return to help their country afterwards.
"It is very easy for Chinese companies or intelligence agencies to approach these students - who are often quite nationalistic - and get them to collect information that might be of either commercial or military interest," said Christian le Miere, Asia Editor of Jane's Country Risk.
The recent defections suggest there are so many such contacts that what they produce could amount to a valuable pool of intelligence, he said.
In one case that came to light in the US, Chinese agents are said to have put pressure on a recruit by telling him that his family in China was at risk if he failed to do what they wanted.
But few such cases come to court, since they are hard to prove and involve people trained not to be caught, said John Fialka, author of a book on espionage, War by Other Means.
"And like rape victims, companies that have been infiltrated are reluctant to talk about it. They don't want people to know they've been hoodwinked by their own staff," he added.
There is often a fine line between what is legal and what is not.
Asian societies tend to have a less legalistic view of intellectual property than some other nations, Mr Fialka said.
But China differs from many other countries because of the way its economic entities are still intertwined with the government and military, he added.
China has about 3,000 "front" companies in the US that exist mainly to obtain technology and military secrets, according to US officials.
Right-wing groups in the US, and opposition parties in Australia, Canada and elsewhere, are warning that Western countries may one day regret allowing China to take advantage of their openness and tolerance.
Chen Yonglin claims Beijing has as many as 1,000 spies in Australia
The dramatic growth in China's economic and political power will soon be matched in the military sphere, they claim.
But China has indignantly denied the spying allegations as fabrications stemming from narrow-minded fears of legitimate commercial and industrial competition.
Louis Turner, chief executive of the London-based Asia Pacific Technology Network, says it is a natural part of the "catch-up" process to place people as close as possible to where the best research is being done and get them to send back information.
"Just as Japan used to effectively steal a few tricks when it was learning from the West, I would be enormously surprised if China wasn't involved in some sort of technical espionage... and no doubt some of this is backed by the Chinese military," he said.
But he said China was genuinely keen on two-way collaboration - and said the main factors behind its rapid progress in science and technology were its sheer size, economic dynamism and willingness to learn.
Some of China's own universities are now producing world-class researchers, and some of its science parks are comparable with Silicon Valley in the 1960s, he added - "but with much more cohesiveness ... and on a much bigger scale".