Security assurance

A security assurance, in the context of nuclear warfare, is an expression of a political position by a nuclear-armed nation intended to placate other non-nuclear-armed nations. There are two types of security assurance: positive and negative. A positive assurance states that the nation giving it will aid any, or a particular, non-nuclear-armed nation in retaliation, should it be a victim of nuclear attack. A negative assurance is not the opposite of this, but instead means that a nuclear-armed nation has promised not to use nuclear weapons, except in retaliation for a nuclear attack against themselves. See also No first use.