Category: Key issues in a nutshell

In this section, you can find one-page introductions to a range of issues pertaining to the nuclear disarmament debate. More in-depth analysis of the different issues can be found in the related downloads, external links and background documents. On some of the issues, we have also published separate ILPI policy papers that can be downloaded, printed or shared.

The status of nuclear weapons

Facts about nuclear armed states and nuclear weapons worldwide


Gives an overview of nuclear armed states, the number of nuclear warheads worldwide, and international control mechanisms and commitments to disarm. 

Nuclear umbrellas and umbrella states

The following text aims to clarify the concept of a ‘nuclear umbrella’ and pinpoints political challenges and debates associated with the topic.


The euphemism of a ‘nuclear umbrella’ is generally understood to cover a form of military cooperation by which one or more nuclear-armed states (‘holding’ the umbrella) provide supposed nuclear protection for one or more non-nuclear-armed states (‘sheltering’ under it). A crucial point to understand about nuclear umbrellas is that they are not necessarily codified by authoritative documents. Rather, nuclear umbrellas are rooted in military and diplomatic practices. A ‘nuclear umbrella’, is a security arrangement under which the participating states consent to or acquiesce the potential use of nuclear weapons in their defence. The related concept of ‘extended nuclear deterrence’ may be understood as the intended effect of a nuclear umbrella. A ‘nuclear umbrella state’ is a state without nuclear weapons under the supposed protection of the nuclear weapons of another state.

ICJ’s Advisory Opinion on nuclear weapons

Summary of the 1996 International Court of Justice opinion


Provides a summary of the 1996 advisory opinion of the International Court of Justice’s (ICJ) on the legality of the use of nuclear weapons.

The Conference on Disarmament

The functions and work of the Conference of Disarmament


Offers an overview of the organization and working methods of the Conference on Disarmament (CD), the multilateral negotiating forum for disarmament and control, as well as a presentation of major issues discussed and negotiated in the CD.

Nuclear-weapon-free zones

The formation of current nuclear-weapon-free zones and possible future zones


This nutshell paper gives an overview of existing nuclear-weapon-free zones worldwide and gives a brief introduction to proposed new zones.