One nation, one state, but a lot of communities and a lot of divergent interests...

A civil war broke out in 1994 between the central government and the southern armed forces. Southern leaders proclaimed the secession and declared a short-lived Democratic Republic of Yemen in May 1994. The war resulted in the defeat of the southerners and the flight into exile of many members of the southern political elite.

In 2000, Yemen obtained some territories in the north (Treaty of Jeddah), but the national cohesion is only a dream.

Since 2007, a southern separatist movement is very active in the former South Yemen and demands the secession from the Republic of Yemen.

Divided between the northerners and the southerners, Yemen is divided too  between the Shia and the Sunni communities. The presence of a very active Al-Qaeda branch amplifies this religious fracture inside the society.

In June 2004, the religious leader of the Zaydis, Hussein al-Houthi, launched a revolt against the Yemeni government.

After a long guerrilla warfare against the central government, the Houthis announced, in the context of the Yemeni Revolution of 2011, their support for the pro-democracy protests and the change of the regime, as had happened in Tunisia, Egypt and Libya.

After the clashes between the Houthis and the government forces and between the Houthis and Al-Qaeda, a coup d’État changed dramatically the rules of the political game on February 6, 2015: the Houthis dissolved the Parliament and created a Revolutionary Committee.

In March, the Yemen’s embattled president Hadi fled Yemen by sea and arrives in the Saudi capital, Riyadh, as Saudi Arabia and its allies launch military operations in Yemen to defend Hadi’s government.

What’s next? A civil war or an international conflict?

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That was a question for the Spring-Summer 2015. Unfortunately, the correct answer is, we know it now, a ‘civil war’ AND an ‘international conflict’, with all the negative consequences for Yemen and its people.

In 1958, the Kingdom of Yemen joined the United Arab Republic (a union between Egypt and Syria) in a loose confederation named the United Arab States.  In 1961 the confederation has been dissolved. In 1962, a republican coup d’État established the Yemen Arab Republic and marked the beginning of a long civil war (1962-1970). 
In the south, under the pressure of the Arab nationalism, Britain accepted in 1959 the recomposition of the two Aden Protectorates and the creation of a Federation of Arab Emirates of the South. In 1962, these Emirates formed the Federation of South Arabia. In 1963, it was merged with the Aden Colony. The rest of the entities (mostly eastern) that had not joined the new federation became the Protectorate of South Arabia.
On 30 November 1967, the Federation of South Arabia, along with Protectorate of South Arabia, gained its independence as the People’s Republic of South Yemen.

In 1925, Yemen obtained the region of Hodeida, a piece of land along the eastern shore of the Red Sea. In 1934, after the signing of the Treaty of Taif, Saudi Arabia (established in 1932) incorporated some northern territories claimed by the Yemeni nationalists as a part of a Greater Yemen (Asir, Jizan et Najran).
The modern history of the other Yemen is very different. Following the conquest of Aden by the Great Britain in 1839, Southern Yemen has been transformed into a British polity. Aden with its hinterland was the only area under full British sovereignty and became a colony in 1937. The other territories formed the Aden Protectorate, divided in 1937 into the Eastern Aden Protectorate and the Western Aden Protectorate.

In 1969, a radical Marxist party gained the power in South Yemen and the country became in 1970 a socialist state, named People’s Democratic Republic of Yemen.

In 1972, the two Yemens accepted the idea of a future political unification of the Yemeni nation (the Cairo Agreement).After a period of political and ideological tensions between the two states, YAR and PDRY renewed later, in 1988, the discussions concerning the unification and the two governments accepted in 1989 a draft unity constitution originally drawn up in 1981. Finally, a united Republic of Yemen had to be created on 22 May 1990.