Nothing can diminish the threat of a disorderly Brexit, or the significance of Boris Johnson’s recent anti-democratic prorogation of parliament. That those stories lead the news is no surprise. But when our government provides crucial support to a campaign of indiscriminate killing in Yemen that has claimed the lives of thousands of people, and this is treated as a footnote in our politics rather than a national scandal, it is plain that something has gone badly wrong.

This week a report by UN experts warned that Britain could be complicit in war crimes through its arming of the Saudi Arabia-led coalition intervening in Yemen’s civil conflict. The report is the latest in a long line from the UN and the world’s most respected NGOs documenting a consistent pattern of violations. The experts note that leading arms providers like the UK “have a specific influence” on the belligerents “and may be held responsible for providing aid or assistance for the commission of international law violations”.

UK, US and France may be complicit in Yemen war crimes – UN report Read more

About 100,000 people have met violent deaths since March 2015, and the blockade imposed by the Saudi-UAE coalition is the primary cause of the world’s worst humanitarian crisis, pushing millions to the brink of famine. Save the Children estimates that 85,000 infants have died from starvation or preventable disease. The UN experts raise the real possibility that starvation is being employed as a war tactic. British complicity in that ought to be unthinkable.

Aerial bombing by the Saudis – frequently indiscriminate – is responsible for most of the civilian deaths, and that bombing is completely dependent on British and American support. The US and UK supply the bombs, the planes that drop the bombs, training for the pilots, and the spare parts and maintenance that keep the planes in the sky. Any idea that these complex weapons systems would simply be replaced by Russia or China were Britain to refuse to provide this support is a myth. The reality is that Washington and London could have stopped the Saudis’ war any time they liked.

This indefensible situation has continued for so long partly because it has not received a level of political attention commensurate with the magnitude of the catastrophe. Our government is to blame for its own policies, but the failure to put sufficient pressure on it to end those policies is something the rest of us are responsible for.

Facebook Twitter Pinterest Yemeni children attend class in a bomb-damaged school in Taez on the first day of the new academic year on 3 September. Photograph: Ahmad Al-Basha/AFP/Getty Images

Politicians of the centre, for example, are never shy of flaunting their supposed internationalist credentials, but many of these same figures either support or have nothing to say about British arms sales to Saudi Arabia. Indeed, most of the British-built planes now pulverising Yemen were sold to the Saudis by New Labour. The Jeremy Corbyn leadership has the correct stance on Yemen in opposing the current British role, but it is hard to believe that the official opposition could not have done more to push the issue up the agenda, given the depth of British complicity in the suffering of that country’s people.

The media also have questions to answer. Academic observers like myself owe a debt to brave journalists like Iona Craig, Bel Trew, Nawal al-Maghafi and Orla Guerin, whose reporting from Yemen is invaluable to our research. But collectively, this story is not given the sustained prominence it needs if the government is going to be held to account. Too much of the commentariat, while enthused by the prospect of Britain staging a “humanitarian intervention” when an official enemy is committing atrocities, appear unable to comprehend a situation where the atrocities are being committed by Britain’s allies with Britain’s help.

These failures extend to wider civil society too. Leading NGOs have done indispensable work in documenting the war’s costs and attempting to raise the alarm. Campaign Against Arms Trade launched a judicial review of UK arms sales whose recent court success has caused a big headache for Downing Street. But large swathes of the left have simply not done enough. It is tragic that the major demonstrations we saw over the invasion and occupations of Afghanistan and Iraq have never materialised to end the sale of arms to Saudi Arabia.

These collective failings have let the government and its Gulf allies off the hook, and Yemeni civilians have paid the price. For a nation that talks endlessly about its place in the world, much of Britain’s political culture remains intensely parochial, self-absorbed, and remarkably casual about the huge humanitarian costs of its behaviour in the global south. This mixture of chauvinism and unconscious racism is of course a legacy of empire. And it is by no means limited to the Brexiteers.

There are, however, competing traditions to be found in Britain, of genuine internationalism and solidarity. Two-thirds of the public oppose arms sales to Saudi Arabia, including half of Conservative voters. There is enormous potential for civil society and the political class to give voice and force to these passively-held opinions. Britain is more than capable of doing right by the Yemeni people. But first we will need to take a long, honest look in the mirror.

• David Wearing is a specialist on UK foreign policy in the Middle East

