Apart from its activities in Somalia, the group also operates in neighboring countries, extending its insurgency to Kenya's border regions with its Jaysh Ayman wing[38] and carrying out a major incursion into Ethiopia in 2022.

[43] Although it is unclear when al-Shabaab was formed, it is understood to have originated as a youth militia within the military wing of the Islamic Courts Union, an umbrella group which provided de facto governance in much of Somalia until the country was invaded by Ethiopia in December 2006.

[47][49] For instance, al-Shabaab denounced the 2006 Ethiopian invasion of Somalia as a "Zionist-Crusader aggression",[47] in which the United States "unleashed its ‘hunting dogs’ in Ethiopia and Kenya" by deploying "the world's crusader forces" to counter the rise of the Islamic Courts Union.

Patriotic themes warning Somalis of the plots from international NGOs, "Christian Crusaders" (United States, Ethiopia, AMISOM) and their collaborators are a regular feature of the movement's propaganda.

It operates several internal departments known as “Makhtab”, including Jabhat (military), Sanaaca (explosives), Da’wa (preaching), Zakat (taxation), Wilayah (local administration), Garsoor (Islamic courts) an intelligence agency known as the Amniyat, and a police force, Jaysh Al-Hisbah.

[77] In 2003, the American Central Intelligence Agency began covert operations targeting the Islamic Courts Union (ICU) by backing anti-ICU Somali warlords[78] with the aim of preventing the formation of a 'Taliban like' state in Somalia that could provide haven to Al-Qaeda.

[84] The invasion resulted in the deaths of many Islamic Courts Union affiliates, leaving a vacuum for the small group of several hundred youth that served as the ICU's Shabaab militia to gain prominence.

[46] By August 2011, al-Shabaab had announced a "strategic withdrawal" from Mogadishu, although, from outlying districts, it continued to exert influence in the city and to launch deadly guerrilla attacks against AMISOM and the TFG.

Some al-Shabaab members viewed the 2010 Ramadan offensive as disastrously ill-conceived, and subsequent territorial losses galvanised internal opposition to the leadership of Ahmed Abdi Godane, who was publicly named the group's emir in December 2007.

[94] As a severe drought afflicted the region, critics, generally associated with the leadership of Hassan Dahir Aweys and Mukhtar Robow,[91][95] opposed al-Shabaab's response to the resulting famine, particularly its obstruction of foreign humanitarian aid to populations in its territories (see below).

[105] Journalist Simon Tisdall viewed the September 2013 Westgate shopping mall shooting in Nairobi, Kenya as a reflection of the internal power struggle, with Godane's hardline globalist faction seeking to exert its authority.

[115][116] Nonetheless, by 2016, al-Shabaab was viewed as significantly weakened by the military campaign against it, with earlier losses compounded in 2014–15 by Operation Indian Ocean, a joint endeavour by AMISOM, the Somali government, and the United States.

[134] By 2020, the group's strategy of semi-territorialism allowed it operate freely in much of rural Somalia, with its primary base in the Jubba River Valley,[47] although air strikes against its leaders continued;[135] and it has recently won military successes against the government.

[139][140] As of July 2022, al-Shabaab is generally considered to be "resurgent",[141] a situation partly enabled by a reduction in the number of American air strikes,[142] and possibly motivated by competition with Islamic State in Somalia, which has been conducting its own expansionary campaign.

[163] More recent films show al-Shabaab distributing humanitarian aid and participating in other community or religious activities – though others are much more gruesome, displaying the corpses of beheaded members alleged to have been spies.

[163] Especially in its early years, it used online chatrooms and discussion forums, encouraging foreign fighters and even military commanders to post updates and field public questions about the state of the jihad.

[163][168] Indeed, although al-Shabaab spokesmen occasionally grant interviews to "carefully selected" local and foreign journalists,[168] social media networks have provided an important channel for interaction with the press, as well as for disseminating information and building support.

Observers guessed that the suspension was a response to the account having issued death threats against Kenyan hostages and against French spy Denis Allex, followed in the latter case by confirmation that the execution had taken place.

This suspension also followed an apparent violation of Twitter's rules: al-Shabaab had recently used the account to claim responsibility for an unsuccessful ambush of a convoy carrying Somali President Hassan Sheikh Mohamud, and to warn that, "next time, you won't be as lucky".

[163] Al-Shabaab had opened a new Twitter account by December that year, with an official telling Al Jazeera that, "The aim is to vigorously challenge defamatory reports in the media by presenting an accurate portrayal of the current state of Jihad in Somalia and countering Western, state-sponsored propaganda machines".

In some cases, group members employed humanitarian aid as a recruitment tool, using relief supplies as bribes and as an incentive to join the militants, whose numbers had decreased due to casualties and defections.

[49] In the United States, the U.S. Senate Homeland Security Committee heard as early as 2009 – from Michael Leiter, director of the National Counterterrorism Center – that American and other foreign fighters were being recruited and trained by al-Shabaab.

[246] In June 2012, General Carter Ham of the U.S. Army said that al-Shabaab, al-Qaeda in Islamic Maghreb (AQIM), and the Nigeria-based Boko Haram were attempting to coordinate their activities, including in funding, training, and explosives.

[246] In 2011, Boko Haram's first suicide bomb attack had been preceded by a public statement warning that "our jihadists have arrived in Nigeria from Somalia where they received real training on warfare from our brethren who made that country ungovernable", which analysts understood as an allusion to cooperation with al-Shabaab.

[253] In October 2015, senior al-Shabaab commander Abdul Qadir Mumin and approximately 20 of his followers in Puntland pledged allegiance to ISIL,[254] establishing what became Islamic State in Somalia (ISIS).

[260] During its early years, al-Shabaab received substantial external support in donations from the Somali diaspora or interested international jihadists,[260] enabled by the weakness of the Somalian government's financial regulation framework and the ubiquitous use of the hawala system for receipt of remittances.

[261] Although al-Shabaab initially appeared a promising alternative to the Islamic Courts Union, its popularity with diaspora donors declined after the Ethiopian withdrawal and as the group gained a reputation for brutality.

[265] In December 2009, adopting Resolution 1907, the UN Security Council imposed sanctions on Eritrea, accusing the country of arming and financing militia groups, including al-Shabaab, in southern Somalia's conflict zones.

[266][267] The International Crisis Group added some credence to Eritrea's denials, suggesting that historical Eritrean support to Somali militants had been aimed at undermining Ethiopia during its 2006–9 invasion, and that Hizbul Islam was more likely a recipient than al-Shabaab.

[276] In recent years, facing territorial losses in urban areas, al-Shabaab has had less recourse to previous revenue streams – notably the charcoal trade, through Kismayo, and the remittance economy – and therefore has relied more heavily on extracting zakat.