A quick quiz. No Googling, no conferring, but off the top of your head: what is currently the world’s worst humanitarian disaster? If you nominated storm Harvey and the flooding of Houston, Texas, then don’t be too hard on yourself. Media coverage of that disaster has been intense, and the pictures dramatic. You’d be forgiven for thinking that this supposedly once-in-a-thousand-years calamity – now happening with alarming frequency, thanks to climate change – was the most devastating event on the planet.

As it happens, Harvey has killed an estimated 44 Texans and forced some 32,000 into shelters since it struck, a week ago. That is a catastrophe for every one of those individuals, of course. Still, those figures look small alongside the havoc wreaked by flooding across southern Asia during the very same period. In the past few days, more than 1,200 people have been killed, and the lives of some 40 million others turned upside down, by torrential rain in northern India, southern Nepal, northern Bangladesh and southern Pakistan.

That there is a disparity in the global attention paid to these two natural disasters is hardly a novelty. It’s as old as the news itself, expressed in one, perhaps apocryphal Fleet Street maxim like a law of physics: “One dead in Putney equals 10 dead in Paris equals 100 dead in Turkey equals 1,000 dead in India equals 10,000 dead in China.”

Most of this amounts to a pretty basic form of racism to which, lord knows, the media are far from immune. Perhaps Eurocentrism would be more accurate. But whatever term you favour, it surely represents the most fundamental form of discrimination one can imagine: deeming the lives of one group of people to be worth less than those of another – worth less coverage, less attention, less sympathy, less sorrow.

Still, blaming the media is the easy option here. It allows everyone else to assume that, left to their own devices, they would be perfectly equitable in their distribution of empathy. But many western consumers of news would be more truthful if they admitted that images of a submerged US city do indeed strike them with greater force than images of a drowning Nepalese one, for a variety of reasons. Perhaps because the American city looks more like their own, or at least more familiar, thanks to films and television. Or simply because havoc in the US is more surprising than natural disaster in, say, India or Bangladesh – developing nations where extreme suffering and regular beatings from the elements have come to seem like part of the terrain.

A tiger killed by floods in the north-eastern Indian state of Assam. Photograph: Uttam Saikia/AP

The media deserve to be attacked for the discrimination they have shown this week. But if those attacks are predicated on a presumption that were it not for all those wicked editors, the audiences they serve would be full of universal fraternity and undifferentiated, boundless compassion, then they are built on shaky foundations.

But I’ve not yet given an answer to my quiz question. Full marks if you put your hand up to say … Yemen. In July the UN determined that it was “the world’s largest humanitarian crisis”. If you think it’s hard to get westerners interested in flood victims in Nepal, just try talking about Yemen.

The scale of the suffering in the Arab world’s poorest country is clear. Since it became the site of a proxy war in March 2015, 10,000 people have been killed, with 7 million made homeless. The UN is especially anxious about cholera, which has already killed 2,000 people and infected more than 540,000. It threatens to become an epidemic. That’s no surprise, given that sewage plants have been among the infrastructure bombed from the sky. The Saudi-led coalition has kept Sana’a airport closed, which means food and medicines cannot get in and the sick cannot get out for treatment. Pictures of gaunt children, listless babies and starving mothers recall the worst of Africa’s famines – but this disaster is entirely human-made.

Nor is this a remote story utterly unconnected to us. On the contrary, the Saudi government is armed to the hilt with weapons supplied by the UK and the US: £3.3bn worth of British firepower in the first year of this vicious war alone. And yet Yemen has barely registered in the western consciousness, let alone stirred the western conscience.

Of course, there are all the usual factors explaining public indifference to horrible events far, far away. But there is one that is relatively new. Before 2003, whenever word came of some distant catastrophe that posed no threat to our own safety, a discussion soon followed on what “we” should do about it. The two sides would take up their positions: the “something must be done” brigade pitted against those who argued that, however awful things were, it was none of our business and we would only make matters worse. Sometimes the latter camp would prevail – think of Douglas Hurd and mid-1990s Bosnia; sometimes, the former: witness Tony Blair and Kosovo.

After Iraq, that changed. Thanks to the invasion, as well as the bloodshed and mayhem in Afghanistan and Libya, the argument is now settled – and the non-interventionists won. The test case is Syria, where Bashar al-Assad has killed hundreds of thousands of his own people – more than Saddam ever did – and yet has been allowed to retain his throne untroubled by outside challenge.

If there has been little western public appetite for action to shield Syria’s people from their dictator, there’s less to protect the people of Yemen. There’s not much interest even in pressuring London and Washington to stop arming the Saudi regime that is responsible for the country’s torment, despite the warnings that Yemen risks becoming the next Syria: its soil soaked in blood, rendered fertile for the next generation of violent jihadists.

This is not the place to re-litigate all the old arguments for and against intervention. (In the Yemen case, there is already western intervention – on the side of those doing most of the killing.) But it is worth noting one consequence of this shift: it’s as if, now that we know that we will do nothing about these distant tragedies, we have lost interest in them altogether. If we are not going to act, then why bother knowing about them?

The result is that the children of Yemen are dying cruel deaths, while the rest of the world ignores them. They are not drowning in Texas or Mumbai. They are dying under a hot desert sun, killed by our allies – and by our inattention.

• Jonathan Freedland is a Guardian columnist