This paper analyzes the effectiveness of U.S.’ coercive diplomacy policy towards Iran carried out through the (re)implementation of sanctions regime after its withdrawal from the so called multilateral agreement ‘JCPOA’ on 8 May 2018. Unsatisfied with the terms of the Agreement, the U.S. administration decided to pull out from the Agreement and immediately implemented sanctions regime against Tehran. Despite the significance of previous studies regarding U.S.’ implementation of sanctions against Iran, I did not found any study that used a specific theory to indicate factors or conditions favoring the success of U.S. sanctions against Iran. In particular, I did not found any literature that analyzes the effectiveness U.S.’ sanctions against Iran after its withdrawal from JCPOA using a specific theory. This paper will fill that gap in the literature by examining the case study using a theory-driven research. The Analytical framework that I apply in this paper is coercive diplomacy theory developed by Tom Sauer which I elaborate into five main variables: objective, demand, threat, time-pressure, and motivation. By examining those factors, this paper argues that U.S.’ coercive diplomacy policy against Iran has been ineffective because of the lack of U.S.’ calculation and considerations to the five variables.This paper analyzes the effectiveness of U.S.’ coercive diplomacy policy towards Iran carried out through the (re)implementation of sanctions regime after its withdrawal from the so called multilateral agreement ‘JCPOA’ on 8 May 2018. Unsatisfied with the terms of the Agreement, the U.S. administration decided to pull out from the Agreement and immediately implemented sanctions regime against Tehran. Despite the significance of previous studies regarding U.S.’ implementation of sanctions against Iran, I did not found any study that used a specific theory to indicate factors or conditions favoring the success of U.S. sanctions against Iran. In particular, I did not found any literature that analyzes the effectiveness U.S.’ sanctions against Iran after its withdrawal from JCPOA using a specific theory. This paper will fill that gap in the literature by examining the case study using a theory-driven research. The Analytical framework that I apply in this paper is coercive diplomacy theory developed by Tom Sauer which I elaborate into five main variables: objective, demand, threat, time-pressure, and motivation. By examining those factors, this paper argues that U.S.’ coercive diplomacy policy against Iran has been ineffective because of the lack of U.S.’ calculation and considerations to the five variables.