After being motivated by the assassination of Usama bin Laden's mentor Abdullah Azzam, he left for Afghanistan in 1992 at the age of 19. While in Afghanistan, he attended several al-Qaeda training camps, including Jihad Wal and Khalden, met several key al-Qaeda figures and ideologues and fought in several different fronts against the communist government of Afghanistan.
When he returned to Algeria, MBM quickly fell into the ranks of the Algerian jihadist group, Armed Islamic Group. From a Jamestown Foundation report on MBM, we can clearly see MBM's beginnings with Hassan Hattab and the beginnings of al-Qaeda in the Islamic Maghreb (which at this time was known as the "Group for Call and Combat--GSPC in their French acronym):
"As the GIA grew increasingly violent under the leadership of Jamal Zitouni and Antar Zouabri, Belmokhtar followed Hassan Hattab in forming the GSPC (Le Quotidien d'Oran, November 13, 2002). In the new organization, Belmokhtar continued in his leadership of the southern zone, with an increasing focus on the procurement of weapons and material. Throughout this period, Belmokhtar and those under his command became a dependable supplier of weapons and material to GSPC elements in the north". From the BBC's profile on MBM: "When the GSPC merged with al-Qaeda in the Islamic Maghreb (AQIM), Belmokhtar headed an AQIM battalion in the desert between Algeria and Mali".
From there, MBM remained an influential member of the GSPC/AQIM until his split with the group in 2012. The split between MBM and the emir of AQIM, Abdelmalek Droukdel, came as a result of a leadership dispute and infighting in the AQIM. Subsequently, MBM formed his own group, al-Mua'qi'oon Biddam (Those Who Sign in Blood Brigade). Al-Mua'qi'oon Biddam formally merged with the Malian Movement for Unity and Jihad in West Africa (MUJAO)--another AQIM splinter--in 2012, with MBM remaining at the helms. His new group, al-Mulathamoon Brigade, is a designated terrorist organization by the US government.
MBM's al-Qaeda Connections:
The aforementioned Jamestown Foundation report says this of MBM's al-Qaeda connections: "After returning from Afghanistan in 1993, Belmokhtar became a key channel for communications between core al-Qaeda and the Algerian jihadi groups. According to his 2005 interview, Belmokhtar claimed to have initiated correspondence with al-Qaeda while the latter was residing in Sudan in the early 1990s. Belmokhtar goes so far as to say that he was tasked with reaching out to al-Qaeda to generate financial and training support for the burgeoning Algerian jihad in late 1994".
The report later says: "Years later, Belmokhtar became the contact for al-Qaeda emissaries to the Algerian arena, starting at least as early as 2002 with Abu Mohamed al-Yemeni (a.k.a. Imad Abdelwahab Ahmed Alwan), a 37-year old Yemeni killed by Algerian troops in the Batna area in September 2002. He was reported to have been sent by core al-Qaeda to oversee the development and expansion of the GSPC’s activities. Following al-Yemeni’s death, al-Qaeda reportedly sent additional emissaries, including Abd-al-Raqib, to liaise with the GSPC’s leadership by way of Belmokhtar ".
From Bill Roggio of The Long War Journal: "Belmokhtar's pledge to Zawahiri and al Qaeda officially dispels the reports that his split with al Qaeda in the Islamic Maghreb, al Qaeda's branch in North Africa, meant he no longer would work with the terror group. He broke off from AQIM in late 2012 due to a leadership dispute with the group. Abdelmalek Droukdel, the emir of AQIM, complained that Belmokhtar took orders only from Al Qaeda General Command and refused to deal with AQIM's bureaucracy.A spokesman for Belmokhtar, Oumar Ould Hamaha, confirmed that Belmokhtar and his group, the Those who Sign with Blood Brigade, or al-Mua'qi'oon Biddam, remain under the orders of al Qaeda central".
Aside from the In Amenas hostage crisis, a few recent trends suggest MBM could be moving further into the global jihadi movement; only posing more of a threat to Western interests. Rather than remaining a menace to local Algerian, Malian or French forces, MBM is "recruiting foreign Jihadi fighters returning from Syria to launch attacks on Western targets".
Being that MBM is recruiting fighters returning from Syria in Libya, this could serve as (a) an opportunity to establish Syrian contacts in which to work with and (b) utilize Libya's lawless south to establish training camps and plot and plan various attacks on Western targets in North Africa, the Sahel, or even in Europe.
Just recently, French intelligence recently uncovered a plot from AQIM to bomb the Eiffel Tower and a nuclear power plant in France. While they have not said (to my knowledge) which "senior AQIM official" the suspect(s) in France were in contact with, it could have very well been MBM. While he is no longer part of AQIM, he is still an ally and still works alongside the group. This could have very well been a miscommunication or a misreporting.
Furthermore, this report from the Combating Terrorism Center, "In 2010, AQIM leader Droukdel declared that AQIM would provide Boko Haram with weapons, support, and training. This collaboration between Boko Haram and AQIM is supported by public statements from both groups, as well as clear indications that Boko Haram’s suicide attack on the United Nations office in Abuja, Nigeria, in 2011 employed tactics that were strikingly similar to bombings by AQIM...Against the backdrop of Boko Haram’s legacy of domestic insurgency in Nigeria, Ansaru and even some actors within Boko Haram have demonstrated a capability and desire to continue executing attacks against Western interests".
If MBM's influence and activity continues to increase, the likelihood of MBM establishing connections with Boko Haram and/or Ansaru (assuming he has not already) will also increase. With Boko Haram wanting to become a larger threat to Western interests, it would make sense to establish connections with a big name actor in the region who already conducts such attacks. Even further, Boko Haram's connections with AQIM could already be the perfect backdrop to establish connections with an established weapon smuggler. It makes even more sense, on MBM's side, to establish these connections with Boko Haram to expand activity, influence, and scope of his operations. If the former head of the MI6 is correct in this Telegraph article in that "MBM has always said that he wants his group to be part of a global terrorist movement and criticises AQIM for being too local. MBM has said that he wants to operate from coast to coast in Africa", then it seems even more likely for MBM to begin to establish connections with groups like Boko Haram, Ansaru, or even ash-Shabaab.
As MBM's influence and activity grows in Northern Africa and the Sahel, his threat to Western interests (including embassies) will also grow. Not only that, but his connections with other militant groups will expand. This includes other militant groups in Africa, other al-Qaeda branches in Africa, and he could even establish ties to various groups inside Syria via his new recruits returning from the jihad there. It seems MBM is becoming, and already is in many ways, one of the West's biggest threats in North Africa and the Sahel.