“Dancing on the heads of snakes” is how President Ali Abdullah Salih of Yemen describes the near impossibility of governing his country. He should know; he’s managed to cling on to power by keeping up the dance for the past three decades. The challenge is certainly considerable: Yemen has been a united country for only 20 years and it’s far from certain that it will remain one. Tribalism make governance a tricky business at the best of times as does poverty: around 40% of its rapidly growing population live on $2 a day. The country’s oil and water supplies are both dwindling at an alarming rate. It’s relations with its northern neighbour, Saudi Arabia, are strained. And since the failed suicide bomb attempt on a plane bound for Detroit on Christmas Day 2009, Yemen is once again in the full glare of international attention as Al-Qaeda’s home base on the Arabian peninsula. British journalist Victoria Clark, who was born in the city of Aden in the south of Yemen when it was still a British …