David Miliband is president of the International Rescue Committee. He is a former British member of Parliament and a former British foreign secretary. The opinions in this article belong to the author.

The cruel aphorism attributed to former Soviet dictator Joseph Stalin has too often proved true.

After the surprise and welcome -- though belated -- call by US Secretary of State Mike Pompeo for a ceasefire in Yemen, maybe the killing of Jamal Khashoggi by Saudi thugs has created a new mantra: one death can be the spark that forestalls the suffering of millions.

It is increasingly clear that the killing of Jamal Khashoggi was a terrible crime rather than an unfortunate tragedy. The feeble excuses from Saudi spokesmen, the changing and contradictory "lines to take", all speak to an old truth: the danger that power corrupts and absolute power corrupts absolutely. No one seems to think that King Salman ordered the killing, so his son, Mohammed bin Salman, needs to explain his role.

The focus of the international community on this murder, and its demands for accountability, cannot however be limited to this one case. The callous disregard for one life should be an alarm bell about decisions by the same government that are affecting the lives of millions. This is where the ceasefire call by Secretary Pompeo could be so significant.

I recently visited Yemen . It is immediately clear that the world's worst humanitarian crisis is in fact a political crisis.

The humanitarian suffering is not a natural tragedy but a man-made catastrophe. After nearly four years of war, precipitated by the coup by the Houthis, and thousands of airstrikes by the Saudi-led coalition in retaliation, Yemen has been brought to its knees.

The current Saudi war plan is making things worse. The bombing campaign from the air causes carnage, but cannot shift the Houthi fighters dug in amongst the local population. No one is winning, except Al Qaeda and ISIS, who gain foothold wherever there is chaos.

So Saudi Arabia's allies in the war effort, led by its closest partners the US and UK, need to deploy their political and military leverage to end the current war strategy. Already, the Saudi-led coalition has intensified its push for Hodeidah in the days since Pompeo's statement in an attempt to change military facts on the ground.

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Secretary Pompeo's ceasefire call needs to be codified immediately in a new UN Security Council resolution. This would stop the increasing violence, would allow humanitarian relief to flow, vital services to be delivered, and the political process essential to a sustainable peace to be driven forward. Britain is the "pen holder" on this file at the Security Council and has no excuse for inertia.

Military support from the UK and US for the war strategy should stop forthwith to keep this from being a rhetorical exercise. Germany has set an example by cutting off sales, but doesn't have the same influence.

This move needs to be backed up by other measures. All of Yemen's critical sea ports must be allowed to function at full capacity and Sana'a airport must be opened to critical humanitarian and commercial traffic. Salaries must urgently be paid to the 1.2 million civil servants across the country, including the doctors and nurses, to provide life-saving assistance to the millions in need.

There needs to be practical measures to make peace sustainable. Treatment of the wounded and prisoner swaps are obvious candidates.

There is also the tougher question of accountability for war crimes that have been documented by the UN.

At the Senate's request, the US Administration is reviewing sanctions against those responsible for Khashoggi's death. This is one avenue for the pursuit of justice which should be widened to include violations of international law in Yemen.

Pressure on the Saudis and their coalition partners alone is not enough. The Houthis and their backers must also feel the squeeze to come to the table in good faith. As Germany is soon joining the UN Security Council, it can use its credibility and links to good effect.

The experienced diplomat Martin Griffiths, special envoy of the UN Secretary General, needs substantive, not just rhetorical, backing. There is a landing zone for peace talks, including assurances about an end to missile strikes from the Houthis, backed by Iran, into Saudi Arabia. But the continued fighting is at best delaying his essential peace-making. At worst, it's making peace impossible.

The suffering in Yemen has gone unacknowledged for far too long - and has emboldened those willing to act with impunity. Jamal Khashoggi's legacy should be accountability not just for the suffering of one, but of millions.