The reunification, preceded by the signing of an agreement (May 1988) for the joint exploitation and demilitarization of the oil frontier areas of Maareb (North) and Chaboua (South), was proclaimed in Aden on May 22, 1990. As president of the newly established Republic of Yemen was simultaneously designated the former president of North Yemen, ʽAlī ʽAbdallāh Saleh, as vice-president of the South Yemeni ʽAlī Salem al-Beid of the Yemeni Socialist Party (PSY) and as prime minister the former president of the People’s Democratic Republic, Haidar Abu Baḳr al-Aṭṭās. The first government of the new unitary state indicated among its priorities the development of infrastructures and relations with other Arab states: the ambiguous position held towards the Iraqi invasion of Kuwait, however, caused the suspension of Saudi (and US) economic aid and the expulsion from that country of approx. 850,000 Yemeni immigrants. Internally, the economic difficulties, aggravated in the South by the sharp rise in prices, produced social unrest and determined growing conflicts between the two parties of the government coalition. In 1991 the Constitution of the unitary state was approved by referendum. In 1993 the legislative elections were held, won by the General People’s Congress (CGP) of President ʽAlī ʽAbdallāh Saleh; Haidar Abū Baḳr al-Aṭṭās of the PSY was confirmed at the helm of the new government. However, conflicts for the joint management of power soon degenerated and in 1994 there was an attempt, soon quelled, of restoration of the Democratic Republic of South Yemen. In September of the same year a new constitution was issued based on the Koranic law and a government was formed controlled by the party of the president ʽAlī ʽAbdallāh Saleh and the Islamic movement El Islah.
In 1995, Yemen’s internal political situation slowly began to return to normal. As Yemeni President ʽAlī ʽAbdallāh Saleh had promised, the government of Sanʽā paid more attention to economic issues by committing to tackle the country’s structural problems decisively. In terms of foreign policy, there were not a few problems that faced Yemen during the same year. The issue of border disputes with Saudi Arabia, resulting from the non-renewal of the Taif Agreement in 1934, re-emerged. The frequent talks between the two diplomats in 1994, the year of the expiry of the twenty-year extension of the agreement and then suspended due to the outbreak of the civil war, led to an initial agreement on the problem of a populous strip of land located along the Red Sea (including the Kuria Muria islands), of which Yemen claimed sovereignty. In the same year the president visited Saudi Arabia and in the following October Sanʽā and Riyadh signed an agreement for the joint fight against drug trafficking and smuggling. In the 1997 general elections, the General People’s Congress (GPC) won a landslide victory to the detriment of the Islamic reformist party El Islah. Only in June 2000 did President ʽAlī ʽAbdallāh Saleh reach an agreement with the Saudi Arabia for the demarcation of the borders, putting an end to the dispute between the two countries. A series of attacks inspired by the opposition Islamic party caused dozens of victims in the first months of 2001, on the occasion of the first administrative elections and the referendum which decided to extend the mandate for the President and Parliament. President ʽAlī ʽAbdallāh Saleh won the 2006 elections. In the north of the country (Saada) the guerrillas of the Shiite minority remained active, the majority in that region, hit several times by military actions by the Saudi army.
In early 2010, President Saleh declared a unilateral ceasefire, while a few days later thousands of people participated in demonstrations in various provinces to demand the secession of the south of the country. In 2011, following the various protests that broke out in Arab countries, protest marches began against the government and President Saleh, culminating in June with an attack on a mosque and an attack on government buildings, in which the premier and the president were seriously injured. who was rushed to a Saudi hospital. Power passed to Vice President Abd Rabbu Mansour Hadi. Returning to his homeland, the president began a series of talks with the opposition, which had the government of the Saudi Arabia. In November, agreements were signed in Riyadh which provided for Saleh’s resignation, his immunity and the interim presidency for two years of Abd Rabbu Mansour Hadi and the formation of a government with the opposition. In 2013, the National Dialogue Conference was established to discuss the main political and social issues and address the institutional transition process following the fall of the former President Saleh’s regime. In 2015, as a country starting with Y according to Countryaah, Yemen plunged back into chaos with the intensification of attacks by Shiite Houthi rebels, originally from the north of the country and supported by Iran and former president Saleh; the incumbent President Abd Rabbu Mansour Hadi took refuge abroad and the Saudi army bombed some rebel positions.