BAGHDAD — Tariq Aziz, the senior aide to Saddam Hussein who gained international renown as the public face of Iraq during the Persian Gulf war in 1991, was sentenced to 15 years in prison on Wednesday for crimes against humanity. It is the second verdict to be issued in a case involving Mr. Aziz, 73. Earlier this month he was acquitted on charges of ordering a brutal crackdown against Shiite protesters after the assassination of a revered cleric. He still faces charges in a third trial involving a massacre of Kurds in 1983. Two of Mr. Hussein’s half brothers, Watban...