After years of negotiation and periodic border wars, the Yemen Arab Republic (North) and the People's Democratic Republic of Yemen (South) formally unified into the Republic of Yemen, with Sana'a as capital. The merger ended a Cold War-era split between a conservative northern state and a Marxist southern one, though tensions over power-sharing would resurface in a brief civil war just four years later.
Yemen had been split since British withdrawal from Aden in 1967 left the south under Marxist rule while the north remained a traditional Arab republic aligned more closely with Saudi Arabia and the West. The two states fought intermittent border skirmishes and even a short war in 1979, but the collapse of Soviet patronage for the south in the late 1980s made unification suddenly attractive to leaders on both sides.
Ali Abdullah Saleh, the northern president, and Ali Salim al-Beidh, the southern leader, signed unification agreements that led to the declaration of the Republic of Yemen on May 22, 1990. Saleh became president of the newly unified state, with al-Beidh as vice president, and the two systems—one capitalist and tribal, one socialist and centrally planned—were meant to gradually merge.
The honeymoon was brief. Disputes over oil revenue, military integration, and political representation led southern leaders to attempt secession in 1994, triggering a short but bloody civil war that the north won decisively. Yemen has remained formally unified since, but the fault lines opened in 1990 have never fully healed, resurfacing again during the Yemeni Civil War that began in 2014.
Key people: Ali Abdullah Saleh, Ali Salim al-Beidh