Over the last few years, a network of enormous detention camps has sprung up across China’s remote northern province of Xinjiang. According to the US State Department, the United Nations and other researchers and activists, they may hold at least a million Uighurs, a Muslim minority Beijing seems increasingly determined to strip of freedom and identity.

It is almost certainly the largest mass incarceration of a racial or religious group since the Holocaust. And it is neither front-page news nor a major part of diplomatic or political dialogue.

In many respects, that is testament to how ruthlessly effective China’s approach has been. The country has been remarkably successful at using its economic clout to minimise international criticism, while limiting outside and foreign access to Xinjiang and making it hard to tell what is truly going on. What experts and activists alike do agree, however, is that the situation for the Uyghurs is deteriorating quickly.

Foreign powers – including Britain – have a host of challenges on which they feel they need China, leaving them understandably reluctant to raise thorny issues like the Uyghurs, Tibet or wider human rights abuses. There are some early signs that this is changing – but not nearly fast or far enough.

What is happening to the Uyghurs could set an appalling precedent for the coming era. Already, Beijing’s cutting-edge technology and diplomatic clout – and complete lack of squeamishness about using it – means China’s Uyghurs are being pressured like no population before in human history. Within Xinjiang, networks of cameras with facial recognition software mean everyone is under continuous state surveillance.

Any displays of behaviour dubbed “foreign” or Islamic – such as wearing a beard or publicly praying – can result in immediate imprisonment. Friends and relatives of Uyghur activists or journalists overseas, such as those for the US-funded Radio Free Asia, are often detained by the dozen. Foreign governments – including Muslim states such as Egypt, Malaysia and Pakistan – have been pushed into deporting Uyghur students back to China, where some are never seen again.

Earlier this month, Britain and Turkey were the only two countries to speak on China’s abuse of Uyghurs at the UN Human Rights Council. Ministers say they have also raised the issue with their Chinese counterparts, including on visits to Beijing. Nevertheless, the topic is strikingly absent from most official speeches and comments, including on Foreign Secretary Jeremy Hunt’s July 2018 trip to China.

Perhaps expecting a business-focused, Brexit-obsessed Conservative government to prioritise the Uyghur issue would always have been over-optimistic. But nor does it seriously appear to have been on Labour’s horizon until earlier this year, when shadow foreign secretary Emily Thornberry addressed London-based Uyghur and other activist groups. “We need to raise awareness of this now, and make it clear it cannot continue,” she said.

Compared to China’s other minorities, such as Tibetan Buddhists and Christians, the Muslim Uyghurs have had relatively few friends in the outside world. With the exception of Turkey, even most Middle Eastern nations have turned on them following pressure from Beijing. China says such steps are necessary to prevent the spread of Islamist militancy.

Small numbers of Chinese Uyghurs have joined groups such as Islamic State, as well as conducting a handful of knife and other attacks in China. But the scope of the crackdown remains out of all proportion to the threat, prompting growing – if still too limited – international condemnation.

This week, a consortium of human rights groups, including Amnesty International and Human Rights Watch called on European governments in particular to step up their criticism of China. Last week saw the United States make its most aggressive comments on the issue, slamming Beijing in its annual review of human rights.

As well as more repeated and public criticism, potential responses could include sanctioning individual Chinese officials linked to the crackdown, as well as restrictions on the sale of surveillance equipment.

How many truly die in the camps is very far from clear – although dozens, perhaps hundreds, of Uyghurs say they have been told of the deaths of relatives. On other occasions, those long missing have been revealed to be alive.

That’s a key reason outside scrutiny is so vital. If those in power in Beijing believe they can continue the crackdown with impunity, they will act accordingly – at worst, opening the door to outright genocide.

Talking about the Uyghurs will unquestionably complicate relations with China just as the world’s great powers desperately need to work together. The clear lessons of history, however, are that not to do so could prove even more dangerous.