The Allies' triumph over Fascism in World War II was, in large measure, a victory over claims of racial superiority or inferiority. Oppressed peoples everywhere took note and began to press claims for freedom and equality.
Those who organized the postwar international order paid attention to these claims. The Charter of the United Nations listed among the purposes of the organization fostering international cooperation "in promoting and encouraging respect for human rights and for fundamental freedoms for all without distinction as to race, sex, language, or religion" (Art. 1). Racial equality was clearly an idea whose time had come, but America's war against German and Japanese racism was fought not by blacks and whites standing shoulder to shoulder but by black units and white units, separate and unequal even as they fought a war against racism.
Cognizant of the inconsistency between America's support for human rights abroad and its segregationist policies at home, President Truman in 1946 appointed a Committee on Civil Rights to offer a way forward for the United States. A report issued by the Committee in 1948 noted the problems inherent in trying to exert moral leadership in the world while failing to address civil rights problems in the United States:
Our position in the post-war world is so vital to the future that our smallest actions have far-reaching effects. . . . We cannot escape the fact that our civil rights record has been an issue in world politics. The world’s press and radio are full of it. . . . Those with competing philosophies have stressed--and are shamelessly distorting--our shortcomings. . . . They have tried to prove our democracy an empty fraud, and our nation a consistent oppressor of underprivileged people. This may seem ludicrous to Americans, but it is sufficiently important to worry our friends. The United States is not so strong, the final triumph of the democratic ideal is not so inevitable that we can ignore what the world thinks of us or our record.
Truman issued an executive order calling for the integration of the United States military, a small first step. At the United Nations, Eleanor Roosevelt brought the work of the UN Commission on Human Rights to a successful conclusion in the matter of the Universal Declaration of Human Rights. It was approved, without dissent, by the General Assembly on December 10, 1948. The UDHR declared, in Article 2, that "everyone is entitled to all the rights and freedoms set forth in this Declaration without distinction of any kind, such as race, color, sex, language, religion, political or other opinion, national or social origin, property, birth or other status."
These were small steps, but to those opposed to civil rights they served as a call to arms. In the aftermath of Truman's reliance on the UN Charter rather than a congressional declaration of war as the legal authority for military intervention in Korea, both isolationists and segregationists (two groups with considerable overlapping membership) rallied around the Bricker Amendment, which (in various guises) was intended to prevent the president's treaty-making power from being used to alter the fundamental norms of the American constitutional system, including the nature of the relationship between states and the federal government. In essence, isolationists supported the Bricker Amendment in order to prevent the United States from becoming further involved in multilateral institutions and segregationists supported it in order to prevent international human rights law from advancing the civil rights movement. To block the Bricker Amendment in the Senate, President Eisenhower was forced to end U.S. involvement in negotiations toward an International Bill of Human Rights.
In essence, opposition to civil rights in the Senate had the ancillary effect of ending American leadership of the international human rights movement. To this day, the United States has still not recovered its position of leadership where human rights are concerned.