Two militant Islamist groups based in the African Sahel have joined forces, marking yet another organizational reboot for al-Qaeda-linked terrorists in one of the world's most lawless regions.

The Sahel has become a new focal point for global counterinsurgency efforts. Roving bands of extremists have long inhabited the region, which runs along the southern border of the Sahara Desert, but the situation kicked into high gear in 2012 when those militants took control of northern Mali, an area roughly the size of Texas.

That effort involved multiple groups of varying backgrounds. It began with the Movement for the Liberation of Azawad, which was made up not of ardent Islamists, but rather of ethnic Tuaregs, who have for decades sought greater sovereignty from regional governments. The Tuaregs were strengthened by a spillover of weapons from Libya's 2011 revolution -- but so were Islamist militants who stole the show within months. By mid-2012, Mali had become a base for extremists linked to al-Qaeda. The insurgents were eventually routed from their Malian strongholds by French troops in early 2013, but they still pose a serious threat to stability in the Sahel.

Even when they controlled Mali, these extremist groups did not comprise a united front. Some claimed allegiance to al-Qaeda in the Islamic Maghreb, or AQIM, which has operated in Algeria for years. Others counted themselves as members of locally-focused groups, such as Ansar Dine, which included many Tuaregs; the Movement for Oneness and Jihad in West Africa, known as Mujao, which had a higher number of formerly AQIM-allied fighters; and Those Who Sign With Blood, which perpetrated the attack on an Algerian natural gas facility that cost the lives of 38 hostages this January.

Those Who Sign With Blood was founded by the one-eyed jihadist and on-again-off-again al-Qaeda affiliate Mokhtar Belmokhtar. According to a Thursday statement from the militants, Belmokhtar -- who is once again loyal to the al-Qaeda allied group he used to command, called Al-Mulathameen or The Veiled Brigade -- and his fighters are joining forces with Mujao.

"Your brothers in Mujao and Al-Mulathameen announce their union and fusion in one movement called al-Murabitoun to unify the ranks of Muslims around the same goal, from the Nile to the Atlantic," said the statement, according to Agence France Presse.

Belmokhtar and Mujao leader Ahmed Ould Amer are both said to have signed the statement, which notes that neither man will lead the new brigade.

Mujao and al-Mulathameen had already forged a working relationship; Thursday's announcement just makes it official. But al-Murabitoun's goals appear to have taken on an expanded scope, as compared to the smaller-scale battles the two groups have been waging over the past two years. The militants promise to "confront the Zionist campaign against Islam and Muslims," which would involve targeting French forces for their role in Mali and even going as far as Egypt to help the Islamists there.

But can the new jihadist group fulfill its ambitions? Mali is no longer the central hub it used to be. It recently held a peaceful election to choose its new President Ibrahim Boubacar Keita, and although 3,000 French troops have initiated their withdrawal, 12,600 U.N. troops are moving in to fill the security vacuum.

Still, vulnerabilities exist all across the Sahel, which is sparsely populated and prone to poverty, food insecurity and estrangement from regional governments. Furthermore, the militant groups now joining forces have gained reputations for evading capture and continuing to launch attacks despite security forces' concentrated efforts to stop them.

The real question is whether the official union changes anything -- and given the long history of al-Qaeda-linked forces making and breaking alliances, some analysts doubt that al-Murabitoun can bring anything new to the table.

"This could be another one of these reorganizations to try to strengthen the group and give it better direction," Andrew Lebovich, an independent analyst focused on extremist groups the Sahel, said to the Associated Press. He added that Thursday statement could be read as a "call to arms."

If that's the case, the formation of al-Murabitoun is not a cause for immediate alarm; it is rather a reminder that the al-Qaeda-linked extremists in Africa's Sahel remain just as determined as ever, despite ongoing efforts to quash the terrorist threat in one of Africa's most hard-to-reach places.