What is Snapback Mechanism? One of the most powerful diplomatic tools ever planned in international relations, the Snapback Mechanism is an emergency brake added to the 2015 Joint Comprehensive Plan of Action (JCPOA). Included in the UNSC Resolution 2231, the Joint Comprehensive Plan of Action (JCPOA) was designed and proposed by Russian Foreign Minister Sergey Lavrov. The snapback mechanism allows for the swift re-imposition of United Nations sanctions against Iran if it violates its nuclear commitments. How Snapback Mechanism Work?