France’s efforts to deport Algerian nationals who are deemed a threat have sparked a diplomatic standoff as Algeria refuses to take them back. While tensions appear centered on immigration, the real driver of the dispute is France’s growing alliance with Morocco, Algeria’s regional rival.

The situation escalated following a deadly knife attack in late February allegedly carried out by an Algerian citizen. In response, the French government sent a list of prospective deportees to Algiers last week. However, despite French authorities having attempted to deport the main suspect 14 times, he remains in France as Algeria continues to deny him reentry.

Vowing a “gradual response” to this refusal, French Interior Minister Bruno Retailleau indicated that Paris would not take Algiers’ decision lightly this time. According to the French daily Le Parisien, the list of deportees included at least 60 Algerians.

Last month, French Prime Minister Francois Bayrou warned Algeria that if it continued to be uncooperative, Paris would have to consider withdrawing from a 1968 agreement with Algiers, which facilitates Algerian immigration to France.