Partial Multinational Joint Task Force victory Multinational Joint Task Force (MJTF) Islamic State Abu Musab al-Barnawi (WIA)(until March 2019) Ba Idrisa ("Abu Abdullah Idris ibn Umar al-Barnawi") (MIA)(from March 2019) Bo Lawan ("Lawan Abubakar") Mustapha Kirmimma (MIA) Mohammad Bashir  Mustapha Jere  Ali Abdullahi  Baba Mayinta Military of ISIL Boko Haram forces ISWAP:c. 3,000–3,500 (2018 estimate)5,000–18,000 (2019 estimate) 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2025 The Chad Basin campaign of 2018–2020 was a series of battles and offensives in the southern Chad Basin, particularly northeastern Nigeria, which took place amid the ongoing Boko Haram insurgency.

The member states of the Multinational Joint Task Force (MJTF), namely Nigeria, Niger, Chad, and Cameroon responded to the increased insurgent activity with counter-offensives.

[8][9] When the insurgents were subsequently defeated and lost almost all of their lands during the 2015 West African offensive by the Multinational Joint Task Force (MJTF), a coalition of Nigeria, Chad, Niger, and Cameroon, discontent grew among the rebels.

They began using suicide vehicle-borne improvised explosive devices[12] and drones which experts considered proofs of support and advice by exiled ISIL members from Syria and Iraq.

[12][13] In addition, ISWAP deviated from Shekau's brutal and autocratic leadership style by organzining a powerful shura or committee that gave the group an element of "democracy".

As he was believed to be a moderate, Nur's death was interpreted as sign that ISWAP was directed by the ISIL central leadership to fully restart its war against the local governments which resulted in the Chad Basin campaign from late 2018.

Following the success of these raids, ISWAP overran and captured the village of Kangarwa near Lake Chad, where it also seized military equipment such as one tank.

The Niger Armed Forces began to target islands on Lake Chad, and the area along the Yobe River at the Niger-Nigeria border from 28 December.

[24] As expected, Boko Haram indeed raided Rann after its garrison had left, setting the settlement ablaze, and murdering 60 people, including the local elders.

[4] A series of clashes between the Nigerian military and ISWAP occurred near Mallam Fatori at the Nigerian-Nigerien border in early February, with both sides claiming to have inflicted heavy casualties on their opponents.

[26] From 14 to 16 February, insurgents launched a number of major attacks, targeting Maiduguri, Buni Yadi in Yobe State, and the border village of Chetima Wangou in Niger.

[29] As part of Operation Yancin Tafki, MJTF increasingly began to apply pressure on the insurgents around Lake Chad from late February.

The air forces of the coalition states struck several rebel camps and vehicles around Lake Chad, reportedly weakening ISWAP significantly.

[30] Insurgent "logistics bases" near Dorou (west of Damasak),[31] Arege, Abadam, Dagaya, Tumbum Gini, and Tumbun Rego had reportedly been destroyed by 11 March 2019.

[30] Heavy fighting also took place along the Nigerian-Nigerien border, as ISWAP troops attacked Gueskerou and the Niger Armed Forces responded with counter-attacks near Lake Chad.

[2] The leadership change was initially not confirmed by either the Islamic State or ISWAP, leading to speculation about whether the reports were true, and why Abu Musab al-Barnawi had been deposed.

[30] MNJTF Chief of Military Public Information Col. Timothy Antigha also argued that the coalition's intense air attacks had greatly damaged the insurgents' supply lines as well as undermined their morale.

About 18,480 people were displaced due to these attacks, while the overall number of refugees in the wider Diffa region rose to 250,000, half of them Nigerians who had fled the violence in their home country.

[36] On 4 April, the United Nations Office for the Coordination of Humanitarian Affairs warned of a "rapid deterioration of the security situation" in the Lake Chad region.

One major joint Nigerian-Chadian operation aimed at evicting insurgents from the Ngala-Gamboru area in Borno State, where they had reportedly sought refuge after retreating from advancing government forces.

Officials declared that this was part of preparations for offensive operations against ISWAP routes between their bases in Buni Yadi (Yobe) and Benisheikh forest (Borno).

[6] On 25 April, Nigerian Defense Minister Mansur Dan Ali declared that "the Boko Haram terror network has been overwhelmed and the leadership structure is presently decimated".

[43] In the same month, Shekau's Boko Haram faction initiated a series of attacks near Lake Chad, targeting Bama, Banki, Ngom, Tungunshe, and Maiduguri.

[46] On 25 May, Shekau's Boko Haram faction released a video eulogizing dead fighters, one of whom was Man Chari (alias "Abu Sadiq al-Bamawi").

[51] Despite the infighting among its forces, ISWAP remained operational and continued to release propaganda as well as initiate attacks in northern Nigeria and southeastern Niger.

In March, the Nigerian and Nigerien militaries claimed to have killed Boko Haram commander Bakura Doro,[14] a statement which was subsequently revealed to be false.