Openness, diversity and tolerance are the greatest strengths of the world’s liberal democracies. But to autocratic regimes like China, these same attributes are vulnerabilities ripe for exploitation.

As reported by the Financial Times on Wednesday, a sitting member of the New Zealand parliament has been investigated by the country’s spy agency in connection with the decade he spent training and teaching at elite military and military intelligence institutions in China, his country of birth.

It is entirely possible that Jian Yang, an MP for New Zealand’s governing National Party since 2011, severed all ties with Chinese military intelligence when he left China in 1994 and has had no contact with any Chinese agents since then. But the fact he was able to enter parliament with very little scrutiny and serve on a committee overseeing foreign affairs, defence and trade, and that his education and military intelligence background appeared nowhere on his official biographies in New Zealand, raises some troubling questions.

People in other western democracies may put this down to naivety on the part of innocent Kiwis. But western intelligence analysts say relatively “soft targets” like New Zealand and Australia are just testing grounds for China’s global espionage activities. In the past five years China has massively expanded its efforts to infiltrate, influence and spy on western democracies and these efforts have already been remarkably successful in countries like Canada, the US and the UK.

It is hard for Mr Yang to argue he is being targeted because of his ethnicity, rather than the decade he spent training and teaching in some of China’s top military and intelligence institutions

In response to reports about his military intelligence background, Mr Yang has suggested he is being “smeared” purely because he is Chinese. This defence goes to the heart of the problem facing liberal democracies. All citizens in these countries should feel safe from being profiled and targeted by intelligence agencies just because of their ethnic background or the country they were born in.

Strong protections of human rights and personal privacy clearly differentiate a country like New Zealand from China, where the ruling Communist party carries out unchecked surveillance on a massive scale and assumes all non-Chinese in the country are potential foreign spies.

It is also true that many western countries, including New Zealand, have an uncomfortable history of racism towards immigrants from certain places, including China. But it is hard for Mr Yang to argue he is being targeted because of his ethnicity rather than the decade he spent training and teaching in some of China’s top military and intelligence institutions. The fact he has consistently advocated international policies that match those of the People’s Republic of China, and that he appears to work closely on many issues with the Chinese embassy in New Zealand, makes his military intelligence background even more relevant.

If he was from, say, Italy, had trained and taught for a decade in Italian military intelligence academies and then became an MP in New Zealand who regularly spoke out on behalf of Italian interests, it would be equally problematic.

It is also hard for Mr Yang to argue that reporting on his background 10 days before a general election in New Zealand is somehow racist persecution when he has gone to some lengths to conceal his past from the general voting public.

If anything, the Chinese intelligence apparatus should take responsibility for fomenting anti-Chinese sentiment abroad through its relentless attempts to recruit ethnically Chinese agents in target countries.

Even if Mr Yang has never worked for China’s intelligence services in New Zealand, his occasional references in Chinese language media to his time at the innocuous-sounding “Luoyang Foreign Languages Institute” would have acted as an intimidating dog whistle for the overseas Chinese community in that country — most Chinese speakers would know, or could easily discover, that the institute is the main linguistics training facility for Chinese military intelligence.

Far from evidence of racism, an investigation by intelligence agencies into Mr Yang’s background and current activities is aimed at protecting those members of the Chinese immigrant community who have chosen to leave authoritarian China and settle in a democracy.

But liberal open democracies are more fragile than most people believe, and without the courage to face up to the potential threat posed by illiberal countries and their subversion efforts, we are all contributing to the erosion of what makes these systems so great.

jamil.anderlini@ft.com