In the late 1960s, British presence in southern Yemen was minimal outside Aden itself. Intense guerrilla fighting throughout the mid-sixties resulted in a British withdrawal from Aden in 1967. With the closure of the Suez Canal, the Yemen's economy was on the verge of ruin, and the new People's Republic of South Yemen, which came into being on 30 November 1967, relied heavily on economic support from Communist countries. It became, in effect, the first and only Arab Marxist state. In 1970 the republic's name was changed to the People's Democratic Republic of Yemen (PDRY).
Mutual distrust between the two Yemens characterised the seventies, and tensions flared into a series of short border wars in 1972, 1978 and 1979. Two presidents of the YAR were assassinated during this period. But under the Presidency of Ali Abdullah Salah of the Hashid tribe, in the late seventies/early eighties, the stability of the YAR steadily improved.
By the end of 1981 a constitution had been drafted in order to implement a merger between the two states. Attempts to consolidate this, however, were delayed by political instability in the PDRY and it was not until 22 May 1990 that the merger was made official.
The new country was named the Republic of Yemen. The border was opened and demilitarised, and currencies were declared valid in both of the former countries. A referendum sealed the unification of the Yemen, and today's Yemen is probably more accessible than it has been throughout its history. Although there is no major tourist industry, visitors are now welcomed on a modest scale, and Yemeni society is fast becoming modernised.