“The invasion of Iraq will surely go down in history as one of the most cowardly wars ever fought. It was a war in which a band of rich nations, armed with enough nuclear weapons to destroy the world several times over, rounded on a poor nation, falsely accused it of having nuclear weapons, used the United Nations to force it to disarm, then invaded it, occupied it, and are now in the process of selling it.”

Quoted in https://www.bbc.com/news/av/world-europe-50265870/mikhail-gorbachev-tells-the-bbc-world-in-colossal-danger Mikhail Gorbachev tells the BBC: World in ‘colossal danger’, BBC World News,(4 November 2019)
2000s

Prime Minister's Questions (15 June 1982) http://www.margaretthatcher.org/document/104968
First term as Prime Minister

A Prescription for Hope (1985)
Context: Combatting the nuclear threat has been our exclusive preoccupation, since we are dedicated to the proposition that to insure the conditions of life, we must prevent the conditions of death. Ultimately, we believe people must come to terms with the fact that the struggle is not between different national destinies, between opposing ideologies, but rather between catastrophe and survival. All nations share a linked destiny; nuclear weapons are their shared enemy.

"Introduction: Thinkability"
Einstein's Monsters (1987)

2010s, 2015, Address to the United States Congress (March 2015)

[No More War!, Dodd, Mead & Company, New York, 1962, 209]
1940s-1960s

A Prescription for Hope (1985)
Context: As no national interest would justify inflicting genocide on the victim and suicide on the aggressor, a prevalent misconception is that nuclear war will never be fought. But the realities of our age compel an opposite assessment. In no previous epoch were adversaries so continuously and totally mobilized for instant war. It is a statistical certainly that hair-trigger readiness cannot endure as a permanent condition. Furthermore, the unrelenting growth in nuclear arsenals, the increasing accuracy of missiles, and the continuing computerization of response systems all promote instabilities which court nuclear war by technical malfunction; by miscalculation, human aberration or criminal act.

"Reaching Global Zero" (8 March 2011) http://www.huffingtonpost.com/valerie-plame-wilson/nuclear-proliferation_b_832399.html
Context: Without doubt, terrorist groups are trying to buy, build or steal a bomb. Furthermore, there is enough highly-enriched uranium (HEU) in the world to build more than 100,000 weapons, and rogue individuals are selling technology on the black market. If terrorists get hold of HEU, they could not be prevented from smuggling it into a targeted city, building a bomb and exploding it.
To my mind, the only realistic solution to this danger is to lock down all nuclear materials and eliminate all nuclear weapons in all countries: Global Zero. I am now dedicated to achieving this goal as a leader of the Global Zero movement. This movement was launched in December 2008 in Paris by an international group of 100 current and former heads-of-state, national security officials, military commanders and business, civic and faith leaders — and in just two years has grown to 300 leaders and 400,000 citizens worldwide.
The group believes that whatever deterrent value nuclear weapons had in the Cold War is now outweighed by the dangers of proliferation and nuclear terrorism. Our international Global Zero Commission has developed a practical, step-by-step plan to eliminate all nuclear weapons through phased and verified reductions.
To build on the progress made to date, we need a worldwide public movement to make Global Zero an urgent global imperative — and to bring all nuclear weapons countries to the table to negotiate multilateral nuclear arms reductions for the first time in history.