The Strategic Arms Limitation Talks (SALT I and II) and Strategic Arms Reduction Talks (START) dealt with long-range nuclear-capable weapon systems in the arsenals of the United States and the Soviet Union. In effect, they were Cold War-era attempts at limiting or restraining the strategic nuclear weapons of the two superpowers. These long-range weapons were characterized by their ability to launch from the territory of one country and strike the territory of the other, otherwise known as intercontinental-range weaponry.
The Intermediate Nuclear Forces Treaty was an attempt to similarly limit superpower nuclear arsenals, but specific to those launched from and targeting sites within Europe.
Post-Cold War efforts have been focused primarily on limiting the proliferation of nuclears weapons (and chemical and biological weapons) to countries not already in possession of such weapons, as well as to existing nuclear-armed countries like Pakistan and China that are always seeking to improve their nuclear arsenals with U.S. or European technology.
There is are a number of international agreements directed at nuclear proliferation, including the Nuclear Suppliers Group, the Wassenar Arrangement, and the Missile Technology Control Regime, which seeks to limit the spread of missile technology needed for countries to accurately target sites in other countries.
There have been many efforts at arms control and anti-proliferation.
Two of the earliest attempts at arms control were made between the US and the Soviet Union. These were the Strategic Arms Limitation Talks. There were two of these treaties, known as SALT I and SALT II. They were meant to reduce the numbers of nuclear weapons that each side had.
As for non-proliferation, the main effort is the Nuclear Nonproliferation Treaty. This treaty specifies that the countries that already had nuclear weapons could keep their weapons. The rest of the countries are not allowed to try to obtain such weapons. This has not been notably successful, with such countries as North Korea, India, and Pakistan obtaining nuclear weapons.