The purpose of this article is to identify the most dangerous challenges and problems encountered by Algeria in the light of the difficult security situation in neighbouring Libya. The collapse of this state has contributed to the escalation of the activities of aggressive groups that threaten the national security of Libya and Algeria, given that in today’s world its own security depends directly on the security of its neighbor. At the regional level, political weakness and the adverse effects of the war in Libya have contributed to the identification of pre-existing security flaws, namely, the rise of organized crime through national smuggling networks along leaky borders and little control, which explains the fears of most of Libya’s neighbouring States, including Algeria. In comparison with the rest of the region, Algeria has extensive experience in the fight against terrorism since the 1990s, when the civil war began. The crises in Libya in 2011 and Mali in 2014 prompted the country’s leadership to make significant adjustments to the doctrine of national security. Algeria seeks to control the Algerian-Libyan border in order to prevent the movement of terrorist groups and weapons inside Algeria, in cooperation with the intelligence services of neighbouring countries. Algeria has made diplomatic efforts to intensify and advance the Libyan-Libyan dialogue between the warring parties. Algeria is an active player at the international and regional levels. It was the Algerian side that had drawn up a coordinated security plan between Algeria and Tunisia, under which a military cooperation Committee had been established to exchange information on armed groups and criminal networks.