Theresa May’s terribly belated appeal to Saudi Arabia to lift the blockade of Yemen and resume essential supplies such as food and medicine must be seen in the context of what the United Nations has described as the “world’s worst humanitarian crisis”, one that has driven the desert country to the brink of famine. Going by the timeline, Riyadh’s war against the Houthi rebels has been waged almost in parallel with the conflict in Syria. Yet another parallel has been drawn with the famine that killed one million people in Ireland 20 years ago when Prime Minister Tony Blair had acknowledged the responsibility of the British government.

In 2017, Whitehall cannot evade its responsibility not least because Britain’s robust support for Riyadh makes it complicit. The British Prime Minister is acutely aware that the heavy bombing of Yemen by Saudi Arabia has been carried out with arms and military support provided by the UK and US. That assistance predates her entry to 10 Downing Street.

Hence the urgent compulsion to visit Riyadh for talks with King Salman and the ominipotent Crown Prince. The world must keep its fingers crossed, hoping that the palace in Riyadh, embroiled in a conflict within the royal family, will lift the blockade that has palpably deepened the tragedy over the past fortnight. The blockade violates the certitudes of international law, and has served to lend a new dimension to a cross-border war within the Arab region, indeed a war seemingly without end.

The crisis is embedded in convenient diplomacy. Saudi Arabia is Britain’s largest trading partner, with Riyadh depending on arms supplies from London. The Saudi blockade has been as cruel as it is inhumane; its lifting will at least ensure the supply of food and medicine to Yemen’s direly impoverished populace. Yemen’s sick and the dying are crying out for life’s essentials. The UN, indeed the voice of the comity of nations, is on test once again. Arguably, the ultimate solution is political. But prospects for a deal are less than slender. In the midst of the starvation, Saudi Arabia’s rivalry with Iran has intensified.

And yet Britain is determined to retain its long-term alliance with Saudi Arabia and to shore up arms exports; £ 4.6 billion worth of weapons sales to Riyadh have been licensed since the war in Yemen began. On Thursday, Mrs May was given no assurance on lifting the blockade. An estimated 10,000 lives have been lost already, not to forget the deaths due to starvation and want of medicines. The conflict has gone beyond the Houthi rebels and the preferred dispensation of the Saudis in Sa’naa. It has gone beyond the ethnic reprisal that Britain has tacitly condoned. It has gone beyond the certitudes of the Arab Spring. The quality of life is strained.