Equality is one of the principles and fundamental rights of human being. There has been lots of talk about equality and justice, but the legal aspect of this principle is still under dispute. Human beings are born equal, so their life has an equal moral value. This principle, along with prohibiting discrimination and bias rejection, has a great impact in the legislative and administrative decisions and is accepted in the Constitution and international norms. But here the important point in this matter is a formation of a paradox in the concept of the principle of equality in today's law. There is a kind of discrimination in the legal and social relationship, within the quest for equality. Privileges that granted to soldiers returning from war and their descendants is an issue that arises during or immediately after every war and because of its discriminatory nature becomes a controversial matter at first glance, and there are widespread opinions regarding this issue. In this article, we try to examine justifying reasons for giving employment priorities to veterans based on the theory of permissible discrimination and equality and to allude to isargaran and veterans' employment priority in Iran and the United States law. Therefore, at first, we examine the theoretical discussions and preference of veterans in America's law. In the next part, in the light of the findings of the first part, veterans and isargaran employment preference will be debated in the United States and Iran's judicial system. Discussing this privilege, we conclude that this privilege is granted to veterans and isargaran according to the theory of permissible discrimination and equality and none of these theories is completely accepted by the legislature of Iran and America and various theories have been used according to time and place.