Despite introducing a multi-party system in 1992 after several decades of one-party rule under his predecessors, throughout his presidency, his Patriotic Salvation Movement was the dominant party.

During the Second Congo War, Déby briefly ordered military intervention on the side of the Congolese government but soon withdrew when his forces were accused of looting and human rights abuses.

During his three decades in office, Chad experienced democratic backsliding,[5][6][7] as well as widespread corruption, including cronyism, embezzlement, and a deeply entrenched patronage system.

[13] Increasingly paranoid, Habré accused Déby, minister of the interior Mahamat Itno, and then commander-in-chief of the Chadian army Hassan Djamous of preparing a coup d'état.

Gaddafi offered Déby military aid to seize power in Chad in exchange for Libyan prisoners of war.

During the following two years, Déby faced a series of coup attempts as government forces clashed with pro-Habré rebel groups, such as the Movement for Democracy and Development (MDD).

[22] Seeking to quell dissent, in 1993 Chad legalized political parties and held a National Conference which resulted in the gathering of 750 delegates, the government, trade unions, and the army to discuss the establishment of a pluralist democracy.

[26][24] Déby, in the mid-1990s, gradually restored basic functions of government and entered into agreements with the World Bank and IMF to carry out substantial economic reforms.

[33] Sudanese president Omar al-Bashir attended Déby's inauguration, and the two leaders agreed to restore diplomatic relations on this occasion.

Déby was in Abéché from 11 to 21 September 2006, flying in a helicopter to personally oversee attacks on Rally of Democratic Forces rebels.

[37] Against this backdrop, in June 2005, a successful referendum was held to eliminate a two-term constitutional limit, which enabled Déby to run again in 2006.

[41] The pipeline was completed in 2003 and praised by the World Bank as "an unprecedented framework to transform oil wealth into direct benefits for the poor, the vulnerable and the environment".

The project established unique mechanisms for World Bank, private sector, government, and civil society collaboration to guarantee that future oil revenues benefit populations and result in poverty alleviation.

[24] However, with Chad receiving only 12.5% of profits from oil production, and the agreement for these revenues to be deposited into a London-based Citibank escrow account monitored by an independent body to ensure the funds were used for public services and development,[43][44] not much wealth was immediately transferred to the country.

[45][46] After Déby won the 2011 Chadian presidential election, Omar al-Bashir decided to visit N'Djamena to attend his inauguration in August.

[48] Because of Chad's strategic position in West Africa, Déby sent troops or played a key mediating role in tackling multiple regional crises, such as Darfur, the Central African Republic (CAR), Mali, as well as the fight against Boko Haram.

[18][49] With the security situation in the Central African Republic deteriorating, Déby decided in 2012 to deploy 400 troops to fight the CAR rebels.

[50][51] In 2006, Chad was placed at the top of the list of the world's most corrupt nations by Forbes magazine,[9][52][53][54] In 2012, Déby launched a nationwide anticorruption campaign called Operation Cobra, which reportedly recovered some $50 million in embezzled funds.

During the 21st Conference of the Parties (COP21) in Paris, Idriss Déby raised the issue of Lake Chad, whose area was a small fraction of what it had been in 1973, and called on the international community to provide financing to protect the ecosystem.

[64] In 2017, the United States Justice Department alleged Déby accepted a $2 million bribe in return for providing a People's Republic of China company with an opportunity to obtain oil rights in Chad without international competition.

[65] In January 2019, Déby and Israeli Prime Minister Benjamin Netanyahu announced the resumption of diplomatic relations between Chad and Israel.

Netanyahu described his visit to Chad as “part of the revolution we are having in the Arab and Muslim world.”[66] Déby signed a bill abolishing capital punishment in 2020.

[69][70] In February 2021, Déby announced Chad would send 1,200 soldiers alongside French troops to the Sahel border between Niger, Mali, and Burkina Faso, to combat al-Qaeda linked groups.

[73] Instead of giving a victory speech, Déby went to command the Chadian soldiers in person on the frontlines fighting the northern rebel incursion by the Front for Change and Concord in Chad (FACT).

[78][79][80][81][82][83] The Chadian Parliament and Government were both dissolved upon his death[81][84] and a Transitional Military Council was formed in its place with his son Mahamat Déby Itno as chairman.

[86] The government ordered a fourteen-day national mourning with flags half-masted and closed public institutions and educational establishments for several days.

[2] This marriage attracted much attention in Chad, and due to tribal affiliations it was seen by many as a strategic means for Déby to bolster his support while under pressure from rebels.

Blogger Makaila Nguebla attributes the defection of many Chadian government leaders to their indignation over Brahim's conduct: "He is at the root of all the frustration.