On the June 5, 2017, Saudi Arabia, the United Arab Emirates, Bahrain, and Egypt alleged that Qatar was providing a safe haven for extremists and terrorist financiers and thereby was breaching its obligations under international law. To coerce compliance, the coalition of countries, led by Saudi Arabia, initiated economic and political sanctions against Qatar. This chapter analyses the legitimacy of this use of unilateral sanctions as a response to Qatar’s shortcomings. It is first argued that the sanctions may be characterised as lawful countermeasures to Qatar’s failures to meet its international obligations to counter terrorism. However, it is then argued that the legitimacy of the sanctions is weakened by both the lack of collective authority for imposition and their impact on individual human rights. Finally, it is suggested that the coalition could reinforce the legitimacy of sanctions by establishing an independent mechanism to mitigate the impact of the sanctions on individual human rights by dealing with issues and complaints, authorising special dispensation and awarding compensation.