As had been the case before in the dispute over the ownership of the Khurma oasis,with King Husain taking the military initiative with a view to creating a fait accompli, it was the Imam Yahya who sought a settlement of the matters at issue with the Wahhabi king by pushing his troops into the areas claimed by him with the support of elements in both, which preferred weak Zaidi control to any closer acquaintance with the strom arm of Ibn Sa’ud. The inevitable clash of frontier guards ensued at a village called ’Aru early in 1931. In the absence of reliable maps at that time it was not easy to determine in this case which side was the aggressor, though before long it became clear that the blame lay with the Wahhabi commander, who had unwittingly trespassed into Yaman territory. — St John Philby, Saudi Arabia