Ahidjo, relying on a pervasive internal security apparatus, outlawed all political parties but his own in 1966. He successfully suppressed the continuing UPC rebellion, capturing the last important rebel leader in 1970. On 28 March 1970 Ahidjo renewed his mandate as the supreme magistracy; Solomon Tandeng Muna became Vice President. In 1972, a new constitution replaced the federation with a unitary state called the United Republic of Cameroon. This is the major cause of tension between the French and English speaking areas of Cameroon. Southern Cameroonians feel the agreement at the Foumban constitution conference is not respected.
Although Ahidjo’s rule was characterised as authoritarian, he was seen as noticeably lacking in charisma in comparison to many post-colonial African leaders. He didn’t follow the anti-western policies pursued by many of these leaders, which helped Cameroon achieve a degree of comparative political stability and economic growth.
On 30 June 1975 Paul Biya was appointed vice president. Ahidjo resigned as president in 1982 and was constitutionally succeeded by his Prime Minister, Paul Biya, a career official from the Beti-Pahuin ethnic group. Ahidjo later regretted his choice of successors, but his supporters failed to overthrow Biya in a 1984 coup. Biya won single-candidate elections in 1983 and 1984 when the country was again named the Republic of Cameroon. Biya has remained in power, winning flawed multiparty elections in 1992, 1997, 2004 and 2011. His Cameroon People’s Democratic Movement (CPDM) party holds a sizeable majority in the legislature.
By April 6, 1984, the country witnessed its first coup d’état headed by col. Issa Adoum. At about 3 am rebel forces mostly of the Republican guard under the orders of colonel Ibrahim Saleh, attempted to unseat Biya’s government. The rebels took charge of the Yaounde airport, national radio station and announced the takeover of government. They attacked the presidency. The civilian northerner who was manager of FONADER Issa Adoum was expected to become the new interim president. Unfortunately, many reasons led to its failure. The principal coup plotters had been arrested by April 10, 1984 and President Biya addressed the nation that calm had been restored.
On August 15, 1984, Lake Monoun exploded in a limnic eruption that released carbon dioxide, suffocating 37 people to death. On August 21, 1986, another limnic eruption at Lake Nyos killed as many as 1,800 people and 3,500 livestock. The two disasters are the only recorded instances of limnic eruptions.
In May 2014, in the wake of the Chibok schoolgirl kidnapping, Presidents Paul Biya of Cameroon and Idriss Déby of Chad announced they were waging war on Boko Haram, and deployed troops to the Nigerian border.
In early 2006 a final resolution to the dispute between Cameroon and Nigeria over the oil-rich Bakassi peninsula was expected. In October 2002, the International Court of Justice had ruled in favour of Cameroon. Nonetheless, a lasting solution would require agreement by both countries’ presidents, parliaments, and by the United Nations. The peninsula was the site of fighting between the two countries in 1994 and again in June 2005, which led to the death of a Cameroonian soldier.