“Nuclear proliferation is on the rise. Equipment, material and training were once largely inaccessible. Today, however, there is a sophisticated worldwide network that can deliver systems for producing material usable in weapons. The demand clearly exists: countries remain interested in the illicit acquisition of weapons of mass destruction.
If we sit idly by, this trend will continue.”

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

"Peace as a Civil Right" from A Prayer for America (2003) [Nation Books, ISBN 1-56025-510-2], p. 76

Source: Ark, Nr. 30-37, 1962.

In a Press conference, regarding the weapon of mass destruction of Iraq. (May 1, 2003) https://archive.is/20130705182739/www.dailytimes.com.pk/default.asp?page=story_1-5-2003_pg4_1
2000 - 2005

News conference http://www.guardian.co.uk/Iraq/Story/0,2763,810093,00.html with then British Prime Minister Tony Blair, October 2002.
2000 - 2005

"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.

Quoted in the New York Times, September 28, 1987, from an earlier public speech. http://www.nytimes.com/1987/09/26/business/amstrad-plots-a-us-invasion.html?pagewanted=all.

From Her Books, I Have Chosen To Stay And Fight, WAR

Nobel lecture (2005)
Context: As long as some of us choose to rely on nuclear weapons, we continue to risk that these same weapons will become increasingly attractive to others.
I have no doubt that, if we hope to escape self-destruction, then nuclear weapons should have no place in our collective conscience, and no role in our security.
To that end, we must ensure — absolutely — that no more countries acquire these deadly weapons.
We must see to it that nuclear-weapon states take concrete steps towards nuclear disarmament.
And we must put in place a security system that does not rely on nuclear deterrence.