The primary aim of this research is to analyze the cause underlying the United States foreign policy by rejecting the Iraqi Kurdistan independence referendum in 2017. The United States is widely known as a superpower country which commonly promotes in securing peace, uphold the value of human rights as well as freedom. A different statement made by the United States during the referendum, questions its well-known value which based on the Universal Declaration of the Human Rights. The policy made by the United States against the referendum aimed underlying its national interest in terms of military security and economic welfare, which not only considering the self-interest of the United States but also preserving relationships with other allies surround the Iraqi Kurdistan region in the Middle East. This paper will analyze the reason behind the United States’ rejection in Iraqi Kurdistan independence referendum in 2017 using theory of securitization and concept of national interest as tools in order to analyze the reason behind the United States’ disagreement. The first thing that this paper want to prove is that the United States disagreement was because of its national interest specifically in military security. Second, its national interest stabilizing economy to achieve economic welfare.