Yemeni politics is notoriously complicated and exotic, with shifting alliances in which former enemies embrace and old friends make strenuous efforts to kill each other. But this exoticism does not mean that the war in Yemen, where the Saudis started bombing on 26 March, is irrelevant to the rest of the world. Already the turmoil there is a breeding ground for al-Qaeda type attacks such as that on Charlie Hebdo in Paris.

So far the Yemen war has been left to the Saudis and the Persian Gulf monarchies, with the US ineffectually trying to end it. The reality of what is happening is very different from the way it is presented. The Saudis allege that they are crushing a takeover of Yemen by the Houthi Shia militia backed and intend to return the legitimate president, Abed Rabbo Mansour Hadi, to power. It has much more to do with their alliance with their old enemy, former president Ali Abdullah Saleh, who still controls much of the Yemeni army. This enabled the Houthis, whose strongholds are in the north of the country, to capture Sanaa easily last September, though UN experts note that the capital "was guarded by no less than 100,000 Republican Guards and Reserve Forces, most of them loyal to the former president".

The problem with the Saudi strategy is the same as that with most military plans. The 19th-century German chief of staff, General Helmuth von Moltke, said that in war "no plan survives contact with the enemy". The same warning was pithily restated more recently by the American boxer Mike Tyson, who said that "everybody has a plan until they get punched in the mouth".

This calamity is particularly bad in Yemen, because the country was in crisis even before the present conflict. According to UN agencies, malnutrition in Yemen is about the same as in much of sub-Saharan Africa and only half the population has access to clean water. The country imports 90 per cent of the grains used for food, but no ships are coming in because its ports are blockaded by the Saudis or caught up in the fighting. In any case it is difficult to move food supplies because of a chronic shortage of fuel. Lack of electricity means that essential medicines in hospitals cannot be stored.