Page "Mutual assured destruction" Paragraph 19

The multiple independently targetable re-entry vehicle ( MIRV ) was another weapons system designed specifically to aid with the MAD nuclear deterrence doctrine.

With a MIRV payload, one ICBM could hold many separate warheads.

MIRVs were first created by the United States in order to counterbalance Soviet anti-ballistic missile systems around Moscow.

Since each defensive missile could only be counted on to destroy one offensive missile, making each offensive missile have, for example, three warheads ( as with early MIRV systems ) meant that three times as many defensive missiles were needed for each offensive missile.

This made defending against missile attacks more costly and difficult.

One of the largest U. S. MIRVed missiles, the LGM-118A Peacekeeper, could hold up to 10 warheads, each with a yield of around — all together, an explosive payload equivalent to 230 Hiroshima-type bombs.

The multiple warheads made defense untenable with the technology available, leaving only the threat of retaliatory attack as a viable defensive option.

MIRVed land-based ICBMs are considered destabilizing because they tend to put a premium on striking first.

It is because of this that this type of weapon was banned under the START II agreement.