The Arab Spring led to the overthrow of multiple authoritarian regimes in the Middle East and North Africa and to the flow of arms and fighters from Libya to Western African countries, triggering the crisis in the Sahel and altering the security landscape of the region. The Sahel, a quite stable region, became vulnerable to the rise of terrorism due to political instability, internal conflicts dynamics and power vacuum which led to ungoverned spaces to be seen as safe havens to terrorist groups. The international community, fearing the spread of terrorism, initiated multiple operations in the region such as an UN mission in Mali – MINUSMA – and the French-led intervention in the G5 – operation Barkhane. After 9/11, a change in perception took place and terrorism now came to be seen as a transnational threat to world peace and stability, leading to the inclusion of a new role during peacekeeping operations – stabilisation – achievable by the use of military power. This study, based on secondary data research, aims to understand the transformation of peace and counterterrorism operations in the Sahel region. The study notes that the view of Sahelian states as fragile and weak and due to that the perfect target for transnational terrorism justifies the West interventions in the region. However, even under a development-security nexus, all interventions were carried out with only one purpose – fight against terrorism – as the global war on terror was seen as required to reinstate security in the Sahel. In this sense, MINUSMA can be seen as a laboratory test, also because it was working side by side with French troops which were under a counterterrorism mandate, which goes completely out of UN’s character. This mission created a dangerous precedent as it goes beyond the normal understanding of peacekeeping missions. This thesis argues that the change of peace and counterterrorism operations in the region happened due to the perception of terrorism as a transnational threat and of the Sahel region as a safe haven for the proliferation of terrorism. Moreover, all interventions had Western interests in mind and not even one was focused on addressing the underlying causes of the conflicts such as political instability, climate change and food insecurity which enlarged the humanitarian challenges in the Sahel.