In these times of turmoil, the escalating crisis in Turkey struggles in the competition for coverage. For some, last week’s failed coup and its aftermath are simply a reminder of an increasingly unstable world, perhaps brought closer to home because the country is a popular tourist resort. But make no mistake: as Turkey’s ever more repressive AKP government wages war against democracy, our own rulers are complicit.

Turkey is our Nato ally. It is a “priority market” for our arms exports – £550m worth. Britain’s new prime minister has declared that this country “stands firmly in support of Turkey’s democratically elected government and institutions”. But rather than condemning the mounting crackdown, Theresa May offered only a weak “call for the observance of Turkey’s constitutional order”, and stressed “the importance of the rule of law”.

Consider the facts. Turkey has long been a serial violator of human rights, but endured all too little criticism – let alone tangible consequences – from its western allies. In the war with Kurdish guerrillas fighting for independence in the 1990s, the country’s security forces destroyed up to 4,000 villages and settlements – often by burning them to the ground. Hundreds of thousands of civilians were displaced, and an estimated 30,000 people died. The country is one of the worst jailers of journalists. “Since 2013, the AKP government has become increasingly authoritarian, increasingly intolerant of dissent, and has resorted to extreme measures such as silencing the press,” says Andrew Gardner, Amnesty International’s Turkey researcher.

The situation only deteriorated after the resumption of conflict with Kurdish PKK fighters in July 2015. “The media faced unprecedented pressure from the government,” was Amnesty’s verdict, and anti-terror laws were used to launch mass prosecutions. Last September British lawyers wrote a damning report about Turkey’s human rights record, citing the rigging of the judiciary, internet censorship, restrictions of freedom of expression, and degrading treatment for detainees. “Turkey’s allies have been remarkably silent in calling upon Turkey to cease these violations,” says Gardner. “Surely the British government can’t be shocked by what’s going on in Turkey. The writing has been on the wall for several years.”

According to Hisyar Özsoy, a senior spokesperson for Turkey’s leftist opposition People’s Democratic party (HDP): “Europe has been so nice about President Erdoğan’s authoritarian tendencies because they think it can help temporarily stop the flow of refugees.”

We must all agree that there was no justification for last week’s failed coup. “Opposing the coup was a matter of principle for us,” says Özsoy, “even though there are so many severe problems about the functioning of democratic institutions.”

The instigators must face justice, not least for crimes Amnesty says include firing into crowds from helicopters. “But it has to be that: justice,” says Gardner. That includes justice for civilians who, under the watchful eye of police officers, attacked unarmed soldiers.

And “justice” does not mean holding detainees incommunicado in unofficial detention centres; it doesn’t mean ill-treatment in detention, which photographs of accused soldiers with bruises and injuries to their faces attest to; and it certainly doesn’t mean the reintroduction of the death penalty, as senior Turkish politicians now threaten. Nor does it mean detentions that range wider than any coup might justify. Judges and prosecutors are among the 7,500 arrested: when they are questioned it is not about the coup, but about their political affiliations.

But our Turkish allies are now exploiting the failed coup to the full by implementing a mass purge of up to 50,000 people, including teachers and university deans. Journalists are having their press cards revoked – without which they are unable to work.

“It’s turning into collective punishment,” says Özsoy. “They will expand this repression and will include all dissents in this country.”

As Gardner puts it, this is “discrimination based on their political opinions”. From severe sanctions to loss of livelihood, those purged will suffer.

And so, critically, will an already battered Turkish democracy and secular system – as well as wider security and peace. “The country is on the brink of civil war,” warns Özsoy. Yes, the west may believe it will win concessions, not least on refugees. But, as the HDP points out, at what longer-term cost? If Turkey descends into political polarisation, violence and conflict – not least when it comes to war with Kurdish fighters – what will that mean not just for Turkey, but for Europe and the Middle East? An attempt to eliminate legal political opposition in Turkey will not be as straightforward as Erdoğan’s goons suggest.

This is where the role of Britain and the west is critical. Whenever the behaviour of western allies – and the responsibility of western states – is highlighted, the response is often “whataboutery”: what about even worse behaviour committed by regimes hostile to the west, such as North Korea? Where are the protests outside Britain’s North Korean embassy?

But our governments are not complicit in North Korean totalitarianism: we do not arm Pyongyang’s dictators, or support them, let alone form alliances with them. Our governments frequently issue indictments of North Korea’s despicable lack of human rights.

When it comes to allies such as Turkey, our government’s failure to publicly condemn, let alone ensure there are consequences, renders it culpable. If we as citizens put pressure on our government to take a stand on human rights abuses in, say, Turkey, Israel or Saudi Arabia, there is at least the possibility of fostering change.

All too often, “stability” trumps democracy when it comes to western foreign policy. Turkey’s western allies have a responsibility to stand against the curtailing of basic rights and freedoms, and to support democratisation. To fail to do so risks peace and security for all of us. These might be febrile times, and many injustices are being committed. But if you believe in democracy and human rights, you have a responsibility to demand that our government stands for both.