Today there is a civil war in Yemen, with the Saudis supporting the Yemen government and the Iranians supporting the Houthi rebels. In the period 1962-1970 there was again civil war in Yemen, but this time the Saudis were supporting the King of Yemen and the Egyptians of Gammal Nasser were supporting his opponents. Great Britain was supporting the Saudis, and the Soviet Union was supporting the Egyptians. Poor Yemen is of great strategic value for the control of the Red Sea, and for attacking Saudi Arabia if you are Egypt in the 60s or Iran in the 2015.
“North Yemen Civil War”