(CNN) Hunger became starvation and is about to lurch into famine. A failing state failed and an economic crisis became a catastrophe. An insurgency became a civil war and then a regional conflict involving Saudi Arabia and the United Arab Emirates.

Over the past decade, Yemen 's vicious cycle has become a downward spiral -- a predictable and preventable spiral. It is a country "in freefall," says the Norwegian Refugee Council. Eight million people are on the brink of famine. UN officials say that number may quickly rise to more than 12 million -- about half of Yemen's population -- unless the fighting stops.

Nearly half a million Yemeni children are chronically malnourished; many are likely to die within the next few months if the conflict continues. Cholera (there were 13,000 cases reported in October alone) and other diseases stalk the land.

A malnourished Yemeni child receives treatment at a hospital in the Yemeni port city of Hodeidah in December. The United Nations has listed Yemen as the world's No. 1 humanitarian crisis.

How did the poorest country in the Arab world and now one of the poorest on earth reach this nadir? And what if anything can be done to mitigate (let alone reverse) what threatens to become the worst famine anywhere in more than a generation?

Decline and fall

Yemen never had much going for it -- few natural resources, a lack of water, endless tribal and civil conflict, religious divides and bad government. But those seem like the good old days. The Arab Spring in 2011 brought protests that turned violent and sparked clan warfare. Yemen's great survivor, President Ali Abdullah Saleh, was critically injured in a rocket attack and replaced. Al Qaeda deepened its presence in several provinces.

In plotting an abortive comeback, Saleh allied with Houthi rebels from the north, who swept into the capital in September 2014 . Fearing that Iran would use the Houthis as a proxy for its regional ambitions, Saudi Arabia and the United Arab Emirates launched what can only be described as a blitzkrieg against Sanaa and other parts of Yemen controlled by the Houthis.

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The coalition's Operation "Decisive Storm" was launched in March 2015. It has been anything but decisive, and rather than vanquish the Houthis the "storm" has destroyed infrastructure and targeted -- accidentally or otherwise -- tens of thousands of civilians.

In a recent study of the coalition's bombing strategy for the World Peace Institute, Martha Mundy said it had "aimed to destroy food production and distribution" in areas controlled by the Houthis, with hundreds of strikes against rural targets. Mundy told CNN that economic warfare was aimed at bringing people to their knees -- essentially: "When we control them, then we'll feed them."

After being driven out of Sanaa, what remained of the Yemeni government set up in the southern port of Aden. In 2016, it moved the central bank there, and stopped paying the wages of hundreds of thousands of government workers. Those scraping by were suddenly in abject poverty. Inflation stoked by massive printing of money worsened their plight.

A blockade designed to choke off supplies to the Houthis also blocked humanitarian aid, accelerating an economic free fall that had already begun. It also (not coincidentally) made it very difficult for the media to cover the war.

Saudi Arabia's western allies have made indignant noises about the scale and indiscrimination of the coalition's campaign -- but have continued to sign lucrative weapons contracts. The bombs that fall from Saudi aircraft are made in the USA ; the planes are refueled by US aerial tankers. The Wall Street Journal reported in September that Secretary of State Mike Pompeo had overruled staff concerned about the civilian toll in Yemen because it would jeopardize $2 billion in weapons sales

To the Trump Administration, the larger goal of containing Iran remained more important than ending the war.

In turn, the Houthis have goaded their enemies with symbolic but useless ballistic missile attacks against Saudi Arabia and committed abuses of their own. They have sequestered thousands of tons of humanitarian aid and often used civilians for cover. Just this week, Amnesty International reported Houthi fighters had taken up positions on the roof a hospital in Hodeidah that is full of injured civilians.

Yemen's lifeline

Hodeidah, the country's largest port, is now at the center of the conflict. It has been under bombardment for much of the past five months. An estimated 300,000 people have fled the city, adding to the already immense burden of Yemen's internally displaced.

Hodeidah and the neighboring provinces account for 40% of the 400,000 children in the country who suffer from severe acute malnutrition, UNICEF says. Aid agency Mercy Corps told CNN that acute malnutrition around Hodeidah has doubled in just the last month. Some areas around the city have seen a five-fold increase in their population.

Still, more than a quarter of a million civilians remain in Hodeidah, and hundreds have been killed since September when heavy fighting resumed. Besides the coalition's airstrikes, aid agencies say that mortar and rocket fire from both sides is exacting a heavy toll.

Frederic Bertrand, head of the Yemen mission of Doctors Without Borders, said Wednesday that attacking forces had "moved quickly around the city" in recent days, and it is almost entirely cut off. The Houthis have blocked off roads with shipping containers and cement blocks.

Hodeidah is not just any city -- more than 80% of the humanitarian aid desperately needed in Yemen arrives there. The International Committee of the Red Cross says simply: "Yemen's survival depends on this city."

Now it may become the next Mosul, the next Raqqa.

An end to the fighting

Only one thing can save Hodeidah, and Yemen: an immediate ceasefire followed by internationally sponsored negotiations, and the free movement of relief supplies.

There are the first tentative steps toward this: US Defense Secretary Jim Mattis said last week negotiations for a truce should begin within a month. And Secretary Pompeo said that Houthi missile attacks on Saudi soil must stop and "coalition airstrikes must cease in all populated areas in Yemen" -- his strongest statement yet.

The UK, another major supplier of arms to the Saudis, echoed the US message.

The indefatigable UN envoy on Yemen, Martin Griffiths, arranged talks in Switzerland in September, but the Houthi delegation refused to travel, citing security concerns. Another effort is planned for Sweden later this month. The coalition's attack on Hodeidah may be an attempt to take as much ground as possible before negotiations begin.

Mercy Corps' Yemen director, Abdikadir Mohamud, says the glimmer of hope offered by recent ceasefire calls is beginning to fade. "Why wait a month for a ceasefire?" he asks.

The Khashoggi effect

Relations between the US and Saudi Arabia have cooled since the killing of journalist Jamal Khashoggi.

The savage irony in all this is that the murder of one man, Jamal Khashoggi, may be prodding Saudi Arabia toward a new approach in Yemen, where 10,000 have been killed (besides the far greater number who have died of hunger.)

The close relations between the Trump Administration and Crown Prince Mohammed bin Salman have cooled since Khashoggi's killing by Saudi operatives close to the Crown Prince. Sources say there are efforts to surround "MbS" with more seasoned advisers. The return of the King's brother, Prince Ahmed bin Abdulaziz, who had been critical of the Yemen campaign while overseas, may also herald a change of policy, according to one diplomatic source.

Ali Shihabi of the Arabia Foundation, a Washington institute close to the Saudi court, says the incompetent execution of the campaign "has exacerbated Yemen's humanitarian crisis and provoked worldwide condemnation."

"The Saudi government will have to prioritize ending this war one way or another," Shihabi says.

But for every day the conflict goes on, many thousands of Yemeni parents watch helplessly as their children waste away. According to the United Nations, one dies every 10 minutes.