There is an increasingly urgent need to assure non-nuclear member states effective international security arrangements against the use or threat of use of nuclear weapons.
It was reported in 1994, that the UN is searching for a common approach or common formula to provide assurance to non-nuclear weapon states against the use or threat of use of nuclear weapons.
In the 1960s, the spread of nuclear weapons was largely checked by U.S. security guarantees, notably to its NATO allies: the famous "nuclear umbrella". The U.S. has already given defense guarantees to Japan, South Korea and Taiwan, and as soon as it has them, it will deploy theater missile defenses to protect its troops stationed in Japan and South Korea. Those defenses will also cover the host nations' territories.