The Hart-Celler Act became fully operational in 1968, by coincidence the Human Rights Year celebrated by the United Nations to mark the twentieth anniversary of the Universal Declaration of Human Rights (UDHR). Endorsed by the UN General Assembly in December 1948, the UDHR echoed those provisions of the 1945 UN Charter that explicitly "reaffirm faith in fundamental human rights," stating, in the precise formulation of the UDHR article 14: (1) Everyone has the right to seek and to enjoy in other countries asylum from persecution; (2) This right may not be invoked in the case of prosecutions genuinely arising from non-political crimes or from acts contrary to the purposes and principles of the United Nations.
Given the crucial role of the United States in the establishment in 1945 of the United Nations Organization—the multifaceted structure that gave institutional and eponymous form to the U.S.–led wartime alliance initially created by twenty-six states in January 1942 "to preserve human rights and justice in their own lands as well as in other lands"—there might seem no possible exception to an American obligation to provide asylum to asylum-seekers. Yet a number of factors show the weakness of this deduction. At the most general level the UN Charter (chapter 1, article 2) forbade any UN "interven[tion] in matters which are essentially within the domestic jurisdiction of any state." The government of the United States, both the Congress and the executive, had traditionally regarded immigration (under the broader heading of the admission of aliens) as a matter determinable solely by the United States itself—a claim of national prerogative amply demonstrated in the senatorial and wider public debate in 1945–1946 over the conditions for American adherence to the UN Charter and Statute of the International Court of Justice. Furthermore and specifically, even the terms of the nonbinding UDHR simply expressed traditional legal practice: the right of an individual to seek asylum was not disputed, but it remained for the host state or sovereign to grant asylum so that it might then be enjoyed—a qualification repeated passim in the Declaration on Territorial Asylum adopted by the UN General Assembly on 14 December 1967. Moreover, even the granting and enjoyment of so-called diplomatic asylum was not unconditional. Such considerations must be borne in mind when we read the later resolution of the General Assembly (24 October 1970) that the UN Charter precepts "constitute basic principles of international law."
As for refugees and would-be asylees, here the UN formulated two documents detailing international obligations toward those in need of such "social and humanitarian" protection: the 1951 Convention Relating to the Status of Refugees and the 1967 Protocol Relating to the Status of Refugees. Although "asylum" is a term absent from the body of both texts, the respective preambles and the context of the documents make the identification clear. The United States became a party to both instruments by signing and ratifying the later protocol, the purpose of which was to remove the temporal and geographical limits of the convention. Aside from the shift of UN (and American) concern from postwar Europe to Cold War Africa and Asia, the accession of the United States to the Refugee Protocol was yet another sign, paralleling the Hart-Celler Act, of the erosion of overt racialism in foreign policymaking. In refugee law, the convention and later protocol established an important textual commitment. In the formula of the convention, article 33 (subsumed in the protocol, article 1): "No Contracting State shall expel or return ('refouler') a refugee in any manner whatsoever to the frontiers of territories where his life or freedom would be threatened on account of his race, religion, nationality, membership of a particular social group or political opinion."
This paragraph gave multilateral treaty form to the principle of nonrefoulement (from the French refouler, to turn back, expel)—the obligation of a state not to expose a refugee within its territorial limits or under its jurisdiction to expulsion into the hands of former or likely persecutors. To this particular commitment two rather different qualifications can be made here. First, the convention's governing condition was the "well-founded fear of being persecuted" in the mind of the refugee, phrasing that would allow judges and officials of the host state to consider a mixture of subjective and objective factors in determining entitlement to asylum for the supplicant. Second (as noted by Hannes Tretter in International Human Rights ), the wording left unanswered the question "how human rights standards and principles of humanitarian law could be guaranteed to war-refugees or refugees fleeing on economic and social grounds, considering … that neither the Convention nor its Protocol offers protection for them." While the United States would become a (conditional) signatory to a number of other human rights treaties—though not, perhaps paradoxically, the 1969 American Convention on Human Rights within an inter-American juridical regime—these parameters of nonrefoulement and the selective extension and denial of asylum to economic, social, and political mass-migrants would constitute part of the framework of U.S. immigration policy in the last third of the twentieth century. (The American Convention on Human Rights must be distinguished from the American Declaration of the Rights and Duties of Man, in which article 27 speaks of the right "to seek and receive asylum," adopted at the Ninth International Conference of American States at Bogotá in 1948, where the Charter of the Organization of American States was approved.)