Hey Melvin.
There are a lot of UN treaties the US haven't ratified because of actual or perceived contradictions with the US Constitution. A few are here...
Convention on Discrimination against Women (CEDAW)
Signed July 17, 1980, never ratified. The US remains one of a handful of countries, including Iran and Sudan, not to ratify CEDAW.
Several good reasons for not signing this. The US would be obligated to federally administer child care, abortion, and many other issue that currently are either left to the state or the individual.
Convention on the Rights of the Child
Signed Feb. 16, 1995, never ratified. Only the United States and Somalia, which has no functional government, have not ratified the Convention.
Again, several good reasons for not supporting this. It would severely interfere with the rights of the parent on how to raise and educate their children. It would also interfere with many states laws concerning criminal justice.
International Covenant on Economic, Social, and Cultural Rights (CESCR)
Signed Oct. 5, 1977, never ratified. The US maintains that economic, social and cultural rights are "aspirational," not inalienable or enforceable. 142 countries have already ratified the Covenant.
UN Framework Convention on Climate Control (UNFCCC) and the Kyoto Protocol
Ratified UNFCCC Oct. 15, 1992 Signed Kyoto Protocol Nov. 12, 1998, never ratified. Of industrialized states, only the US, Australia, and Israel haven't ratified the protocol. The US did ratify the UNFCCC, but has not complied.
The less said about Kyoto the better.
Comprehensive Test Ban Treaty
Signed Sep. 24, 1996, never ratified. The U.S. Senate voted in 1999 to reject ratification of the test ban treaty. Taking another step away from the agreement, the Bush White House released the Nuclear Posture Review (NPR) in early 2002 hinting at a return to testing and reserving the right to use nuclear weapons in a first-strike attack. The NPR also states that arms reductions can be reversed.
US defense policy is conducted solely at the behest of the American people.
Anti-Ballistic Missile (ABM) Treaty
Signed and ratified summer 1972, US unilateral withdrawal Dec. 13, 2001. The U.S. became the first major power to unilaterally withdraw from a nuclear arms control treaty.
Biological and Toxin Weapons Convention (BWC) and Draft Proposal
Signed April 10, 1972, ratified March 23, 1975, rejected Draft Proposal in June, 2001. After the BWC was drafted in 1972, its 144 state parties agreed that the convention's enforcement mechanisms were inadequate. An "Ad Hoc Group" formed in 1994 to negotiate changes. When the group presented its draft proposal in 2001, the U.S. rejected it and refused to return to negotiations, effectively derailing the treaty.
The US wanted to support it but it's enforcement protocols sucked.
Chemical Weapons Convention
Signed Jan. 13, 1993, ratified Apr. 25, 1997. The U.S. ratified the Convention, but set extensive limitations on how it could be applied in the U.S., essentially gutting its provisions. The U.S. specifies that material cannot be transferred outside the country for testing, limits which facilities can be tested, and gives the President the right to refuse inspection on the grounds of "national security."
The US isn't going to allow UN officials to crawl around top secret US facilities.
Mine Ban Treaty
Never signed. The U.S. remains the only member of NATO besides Turkey, and the only state in the Western Hemisphere besides Cuba, not to sign the Mine Ban Treaty. The U.S. used anti-personnel land mines in the first Gulf War, and claims that land mines are essential to protect US soldiers in heavily armed places like the demilitarized zone between North and South Korea.
The problem isn't land mines but leaving them around when the conflict is over, when at all possible the US doesn't do that.
Rome Statute of the International Criminal Court (ICC)
Signed Dec. 31, 2000, unsigned June 6, 2002. In 2002, the US made the unprecedented move to "unsign" the treaty establishing the ICC. Since then, the US has systematically undermined the ICC by signing bilateral agreements with states to exempt US military and government personnel from the court's jurisdiction.
US soldiers...following their orders...tried in the Hague...not going to happen, even with Obama.