Are Nuclear Weapons Illegal? Yes, But It Doesn't Matter

The international community has repeatedly condemned nuclear weapons as illegal, but nuclear-armed nations aren’t relenting. KCNA via Reuters

The Nobel Peace Prize was awarded on Friday to the International Campaign to Abolish Nuclear Weapons (ICAN). The group was recognized for its mission to "draw attention to the catastrophic humanitarian consequences of any use of nuclear weapons and for its groundbreaking efforts to achieve a treaty-based prohibition of such weapons," according to the Nobel Committee.

North Korean leader Kim Jong-un and President Donald Trump have made the issue of nuclear disarmament more pertinent than it has been in decades, with their repeated threats of nuclear annihilation. After winning the award, ICAN Executive Director Beatrice Fihn was asked if she had a message for them. "Nuclear weapons are illegal," she said. "Threatening to use nuclear weapons is illegal. Having nuclear weapons, possessing nuclear weapons, developing nuclear weapons is illegal, and they need to stop."

Related: What Is the International Campaign to Abolish Nuclear Weapons?

But just how illegal are nuclear weapons, and can anything prevent the world's superpowers from developing them?

In 1996, the International Court of Justice (ICJ) delivered an advisory opinion titled "Legality of the Threat or Use of Nuclear Weapons." The opinion followed requests from both the World Health Organization and the United Nations General Assembly. The ICJ concluded both that "the threat or use of nuclear weapons would generally be contrary to the rules of international law applicable in armed conflict, and in particular the principles and rules of humanitarian law," and that "states must never make civilians the object of attack and must consequently never use weapons that are incapable of distinguishing between civilian and military targets."

The "rules of international law" that the use of nuclear weapons would violate are numerous. There's the 1868 Declaration of St. Petersburg (illegal because the loss of civilian life wouldn't be minimized), the 1907 Hague Convention (illegal because there would be "no guarantee of the inviolability of neutral nations"), the 1948 Universal Declaration of Human Rights (illegal because the resultant radiation would interfere with the health of innocent people), the 1949 Geneva Convention (illegal because protection of health workers, expectant mothers and the sick would not be ensured) and the 1977 Geneva Convention protocol (illegal because of the loss of civilian life and damage to the environment).

Nuclear weapons would also appear to violate the 1928 Kellogg-Briand Pact, an international agreement that prohibited war as an instrument of national policy, stating that war could not be used to settle "disputes or conflicts of whatever nature or of whatever origin they may be, which may arise among them." Representatives from the United States, France, the United Kingdom, Germany, Italy, Japan and several other international powers signed the treaty, which proved effective for about a decade before World War II commenced.

Though the international community has ruled multiple times over multiple decades for multiple reasons that the use of nuclear weapons is illegal, there is still plenty of gray area surrounding the issue. The 1996 opinion issued by the ICJ also included an observation that it could not "reach a definitive conclusion as to the legality or illegality of the use of nuclear weapons by a State in an extreme circumstance of self-defense, in which its very survival would be at stake."

This is open to interpretation, of course, and not only makes such restrictions all but impossible to enforce, it makes the use of nuclear weapons defensible. Progress toward clarifying the international stance toward the legality of nuclear weapons was made this summer, however, when the United Nations officially adopted the Treaty on the Prohibition of Nuclear Weapons.

The world's nine nuclear-armed nations refused to participate in the vote, and the United States, the United Kingdom and France even released a joint statement detailing how the initiative "clearly disregards the realities of the international security environment." Nevertheless, groups like ICAN, which supported the treaty, see it as a significant step toward disarmament. "This treaty is a strong categorical prohibition of nuclear weapons and is really rooted in humanitarian law," said Fihn, adding that though no one expected nuclear-armed nations to comply, it "provides a path" for them to do so in the future.

As long as Kim Jong-un is pumping resources into North Korea's missile programs, it's hard to envision disarmament. While the statement from the United States, the United Kingdom and France in response to the Treaty on the Prohibition of Nuclear Weapons preached the necessity of deterrence, Fihn finds flaws in the theory. "[Deterrence] only works if you are ready to use nuclear weapons; otherwise the other side will call your bluff," she said, adding that its efficacy is "based on a perception that leaders are rational and sane."