It was because of China's massively increased espionage activities in recent years that in 2004 the Australian Security Intelligence Organization set up a new counter-espionage unit.
But the problems China poses for a country such as Australia in the security and espionage field extend far beyond what might be regarded as traditional espionage.
Beijing has the most unified and co-ordinated sense of national power of any big nation on Earth. Modern China is not a democracy, but it is a very effectively functioning modern state.
It has a highly competent bureaucracy that seeks to penetrate all sectors of Chinese society and serve what the ruling Communist Party regards as the broader national interest. This includes monitoring, and where possible influencing, Chinese business people and students in their activities overseas.
This is a highly elusive matter, extremely difficult to quantify.