When US senators resume their work later this month, they'll again face the challenge of ratifying a treaty. They will be required to give their advice and consent by a two-thirds vote to expanded membership of the North Atlantic Treaty Organization.
Historically, senators haven't been fond of treaties. Significant international agreements such as the 1919 Versailles Treaty have failed to get the necessary votes. Administrations, facing possible defeat, put off tests of others, such as the Strategic Arms Limitation Agreement with the Soviet Union (SALT II) of 1979. Some, such as the Panama Canal Treaties (1979), the North American Free Trade Agreement (1993), and the recent Chemical Weapons Convention gained the necessary votes only when an administration was prepared to wage an all-out effort on behalf of the agreement.
According to the Congressional Index, 70 treaties signed by the US and submitted to the Senate in the last 50 years remain unratified. These include important international conventions on human rights; economic, social, and cultural rights; biological diversity; the elimination of all forms of discrimination against women; the law of the sea; nuclear safety. Senate reservations about treaties stem from a number of factors - some valid, some questionable. When the provisions of a treaty conflict with the US Constitution or federal or state law, reservations are understandable. The UN Convention on Economic, Social, and Cultural Rights, for example, relates to education, jobs, and cultural activities that, in the US, are the province of states or the private sector. Senators are sensitive, also, to the preservation of US sovereignty. Any agreement that would seem to give foreign entities the right to intervene in American domestic affairs is likely to have a difficult road to ratification. The costs of international obligations are another inhibiting factor. …