This article has been updated to reflect the latest threat of famine.

The United Nations is warning that Yemen is on the brink of the world's worst famine in decades and that millions of people will die as a result.

The UN Humanitarian Chief, Mark Lowcock issued the warning after briefing the UN Security Council. "There will be a famine in Yemen. It will not be like the famine which cost 250,000 people their lives in 2011. It will be the largest famine the world has seen for many decades, with millions of victims."

The UN had already described Yemen as the worst humanitarian crisis in the world. Now, after a ballistic missile was fired towards Riyadh, the Saudi-led military coalition that is fighting Houthi rebels in the Yemen has tightened its air, land and sea blockade. Humanitarian flights delivering vital aid can no longer operate and food prices have soared. Seventeen million people are threatened by food shortages. In the areas worst hit by the fighting, 6.8 million people are one step away from famine. There is no drought to blame for the emaciated faces, the sunken eyes and the withered limbs of Yemen’s children.

Cholera epidemic

The biggest cholera outbreak in modern history is adding to the humanitarian crisis in Yemen. Save the Children says the millionth case will be recorded before the end of the year. The World Health Organisation has recorded 815,000 confirmed cases and 4,000 new cases a day are being diagnosed. Half of those new cases are among children under 18. The WHO has recorded 2,156 deaths from cholera in Yemen.

A conflict with complex roots

How did Yemen get to where it is today?

If you did a quick Google search to try and understand the causes of the conflict, you could end up more confused than before you started. In some places, Yemen is referred to as a proxy war, a sectarian conflict with the Saudis pitted against an Iranian-backed rebel group. In others, the war is described as an attempt to stabilize a fragile state, seize back power from rebels, and restore the legitimate government.

Putting aside these sometimes conflicting explanations, any effort to understand the situation must start with the recognition that for Yemen and its people, instability is unfortunately nothing new. “Yemen is a country that’s witnessed conflict for a while,” Adam Baron, a visiting fellow at the European Council on Foreign relations and a former Yemen-based journalist, told us. The current situation is so complex precisely because it is hard to untangle from what came before it.

“Effectively, you have a number of conflicts inside other conflicts that are inside other conflicts,” Baron explains. “It’s debatable what the ultimate root of the conflict is.”

That said, there are a few recent events of which we can be sure. In 2012, in the wake of the Arab Spring that spread across the Middle East, long-time Yemeni President Ali Abdullah Saleh was forced out of office. His successor, Abdrabbuh Mansour Hadi, had his work cut out: a separatist movement in the south of the country, terrorist attacks and dire poverty, to name just a few of the problems he faced.

Houthi rebels – whose members belong to the Zaidi sect, a Shia group made up of around 40% of Yemen’s Muslims – seized this opportunity to occupy large parts of the country, eventually leading President Hadi to flee.

In response to the rise of a group that some – rightly or wrongly – saw as supported by Iran, Saudi Arabia launched an air campaign, in coalition with eight other Arab states. Their stated goal was to reinstate President Hadi and drive out the rebel forces.

Just how bad is the situation?

More than two years after the launch of Saudi-led air strikes in Yemen, the toll has been a heavy one. As Baron points out: “the numbers are almost inconceivable.”

The charity Mercy Corps says at least 40,000 people have been killed in the war. That’s seen by many as a very conservative estimate.

The UNHCR said in April 2017 that 2 million people were internally displaced. Today, around 80% of the country is in need of humanitarian aid, and the Saudis stand accused of violating international humanitarian law by deliberately targeting civilians.

It seems hard to believe that destruction on such a scale could have been overlooked by the international community for so long. There are a few reasons for this, argues Rafat Al-Akhali, a former minister in Yemen’s government, and a member of the Forum’s Young Global Leaders community.

For one, the complexity of the situation makes it a difficult narrative to sell to a wider public: people want an obvious “bad guy” – think Bashar al-Assad in Syria – but it’s not quite as clear cut in this case.

More importantly, though, one of the main reasons why many people have not heard about this sooner is because some of us are – at least through our governments – involved.

“Major Western powers – the US, the UK, among others – are effectively part of the war, as they’re providing support to the Saudis. There’s therefore been no incentive for their governments to highlight what’s happening in Yemen,” Al-Akhali told us.

An end game in Yemen?

While the wider public might only just be waking up to this crisis, the United Nations has made several attempts to bring about an end to the conflict – with little success. Towards the end of October, a sixth UN-brokered ceasefire failed, with each side accusing the other of violating the terms.

Al-Akhali says he is confident that in spite of this, an agreement could still be reached, “There is still room for negotiations.” But even if that were to happen, there’s no saying what the future holds for Yemenis, who have been caught between warring factions.

“Yemen was already the poorest country in the Middle East region even before the war started. As the conflict has escalated, the small economy that existed has crumbled,” Al-Akhali wrote in a New Statesman article.

Baron shares his concerns. “What you’re looking at is a lost generation – even if you put aside those in need of humanitarian aid, you still have tons of kids out of school, growing up in an environment where the few available jobs are largely found behind the barrel of a gun.” And the consequences of that will be felt far beyond Yemen’s borders. “The fall-out from the conflict will likely unsettle the region – if not the world – for some time.”

If photos of starving children are not enough to motivate the international community into action, then perhaps the idea that Yemen’s collapse could create even more instability in an already volatile region will.