To Possess or to Not Possess: The Question of Nuclear Weapons

“The purpose of war within Judaism is to restore peace.”[i]  While this statement is one potential description of the stance Judaism takes on war, it is by no means the only approach. Within Judaism, the laws of war are very complicated, with authorities disagreeing on what types of war are justified, and what is permitted during war. Rabbi J.D. Bleich points out that in Halakhah, “War is sanctioned only when commanded by God, i.e. when divine wisdom dictates that such a course of action is necessary for fulfillment of human destiny.”[ii] This limitation, that a war must be permitted by God, results in a complex treatment of war within Halakhah, causing disagreement about what exactly this instruction implies.  This article will examine some of the halakhic restrictions on war and takes the perspective that Halakhah sees war as a necessary tool for achieving peace but wants to minimize warfare as much as possible.

According to Rambam, war is classified as either a milhemet mitsvah (obligatory war) or a milhemet reshut (permissible or voluntary war).[iii]  A milhemet mitsvah is a war that the king is allowed to wage because God has commanded him to do so, such as war against Amalek or the seven Canaanite nations, or a war in which other nations attacked Benei Yisra’el. A milhemet reshut is a war that the king starts, with the approval of beit din, in order to widen the borders of Erets Yisra’el or to increase his own honor. Not included in either of these two categories, however, is a war of pre-emptive self-defense, a war that Israel may start in order to prevent a forthcoming attack by an opposing nation. According to Jewish tradition, states R. Michael Broyde, this type of war “is not considered to be war,” but is simply an extension of the law allowing self-defense against a rodef (pursuer), and therefore does not need to be explicitly mentioned.[iv] However, wars that are not “based on self-defense needs,” and do not fall under the other permitted categories, are illegal in Jewish law, such that any killings that would take place during such wars would be considered murder.[v] Perhaps the reason for this limitation on war is the great value that Halakhah places on human life. Judaism’s understanding of the worth of each living human is evident from the fact that Jews are required to do everything they can to save a life, with the exception of breaking the three cardinal sins of idolatry, adultery, and murder. The emphasis that Judaism places on the value of life creates a tension when it comes to war, but perhaps this tension explains why the codified laws of war are so detailed and well thought out.

War involves not only manpower and strategy, but weaponry as well. While certain weapons, like guns or swords, are permitted for use in war by Jewish law, the utilization of nuclear weapons is not as clear-cut. Using nuclear weapons would be halakhically unacceptable if it were clear that such usage would cause “large scale destruction of human life on the earth as it currently exists.”[vi]  This notion is based on a Gemara[vii] that “explicitly prohibits the waging of war in a situation where the casualty rate exceeds a sixth of the population.”[viii] As nuclear weapons have the potential to destroy vast expanses of land and kill millions of people, they may fall under this category in certain cases. Lord Jakobovits, former Chief Rabbi of England, notes that “it would appear that a defensive war likely to endanger the survival of the attacking and the defending nations alike, if not indeed the entire human race, can never be justified. On this assumption, then, that the choice posed by a threatened nuclear attack would be either complete destruction or surrender, only the second may be morally vindicated.”[ix]

While some authorities prohibit the use of nuclear weapons that have the power to cause large-scale destruction, questions still arise about whether countries are allowed to possess the weapons even if they do not ever plan on using them. Are countries permitted to possess nuclear weapons as a deterrent from attacks, or would ownership itself be prohibited by dint of the fact that such weapons can never be used?  If such ownership is, in fact, forbidden, would ownership of nuclear weapons that could be used for small-scale attacks in which the death toll would be less than one-sixth of your population be permitted, even if the owner never plans on using the weapons? Does deterrence through the possession of nuclear weapons, which have the potential to cause mass destruction, actually have the ability to promote life if this deterrence successfully discourages war?

Rabbi Michael Broyde analyzes the halakhic aspect of this issue by comparing nuclear armament to lying in order to save a person’s life. Rabbi Broyde explains that just as “lying to save an innocent person’s life is permissible,” so too “lying to save one’s own life” is justifiable as well.[x]  Similarly, threatening to harm another party in order to save lives, even without ever intending to harm that party, would be permissible. Since nuclear armament as deterrence is a type of threat that is employed to save lives, possessing nuclear weapons as a deterrent should, by extension, be permitted by Jewish law.

During the Cold War, two Orthodox rabbis, Rabbi Maurice Lamm, a former YU professor and communal leader, and Lord Jakobovits debated whether Western powers should collect nuclear arms as a deterrent to forestall attacks from the Soviet Union, which was building up its own arms at the time. Rabbi Lamm felt it was permissible and even necessary, while Lord Jakobovits felt that it was improper to even begin to collect arms, since nuclear weapons can never be used. Elliot Dorff, rector at the American Jewish University, points out that the response of Lord Jakobovits hints to pacificism “as an undercurrent within Judaism,” and that Jakobovits’s feeling is an indicator of the way many Jews approach the idea of war between nations.[xi]

Arthur Waskow, a leader of the Jewish Renewal movement and founder of the Shalom Center (an organization that discourages nuclear armament), offers further insight into the reasons behind the anti-armament approach. Waskow argues that armament for the purpose of intimidation alone is not enough of a justification for compiling nuclear arms, as such intimidation “is not a good means for self defense.”  Waskow’s argument seems to be that stockpiling weapons merely for the purposes of intimidation may lead to a reality in which the arms are actually needed for self-defense, but the government will not want to use them.  He further claims that possession of these weapons will inevitably lead to destruction when saber-rattling gives way to actual deployment of warheads, making it irresponsible to even begin to collect nuclear weapons.[xii] Thus, according to Waskow, the justification for possessing nuclear arms based on self-defense fails.

The issue of nuclear weapons is not only a halakhic issue, but a moral one. As such, every major demonination within Judaism is represented strongly by different leaders who have expressed moral concerns with nuclear armament. For example, Reform Rabbi David Saperstein, Reconstructionist spokesperson Arthur Waskow, Conservative Rabbi Samuel Dresner, and Orthodox Rabbi Walter Wurzberger all came out strongly against armament because of the threat that nuclear arms hold to the human race.[xiii] As Moshe Lichtenstein points out when discussing nuclear wars in reference to the war of Gog U’Magog, that in a nuclear war, “even the… winners lose.”[xiv]   That these four rabbis, though they do not have the same views on Halakhah, still had similar opinions on using nuclear weapons points to the moral element of the question. It is a question about the chances people should take with technologies that could potentially do major damage to the world.

Many scientists who played a role in developing nuclear bombs, including numerous prominent Jews, advocated for disarmament later in their lives.[xv] Albert Einstein, who developed the theory of relativity that paved the way for the invention of the atom bomb, strongly urged President Roosevelt to build a bomb before Nazi Germany would. Later, however, he discouraged the use of nuclear weapons. Leo Szilard helped conduct the first nuclear chain reaction; he too later demanded the curbing of atomic weapons. Joseph Rotblat, a scientist who worked on the Manhattan Project (the secret government-sponsored research program which developed the first nuclear weapons), quit the project in 1944, and in 1955 joined Einstein in discouraging armament. J. Robert Oppenheimer headed the Manhattan Project, but three months after his team detonated the first hydrogen bomb, he resigned and discouraged further development of nuclear weaponry.  This tendency of scientists working on a nuclear project to turn their backs on it perhaps stemmed from a feeling that while nuclear weapons can be helpful as deterrents, the risks involved in possessing and maintaining them are too great. With their informed perspective, they fully understood the destructive capabilities of nuclear weapons if used inappropriately, and therefore warned against their development.

This question has particular relevance to the State of Israel and its quest to defend itself against the very real threats posed by hostile countries who are in the process of developing nuclear weapons, such as Iran. In the late 1950s, Shimon Peres launched the Israeli nuclear program in Dimona, and it is well-known that Israel has been developing its nuclear program ever since. (This is evident from the case in 1992 where forty-four employees sued the plant for radiation poisoning.)[xvi] However, the halakhic, as well as the moral, question as to whether Israel could ever use weapons created from their nuclear plant, or even maintain them as a deterrent, will be continually debated. Nuclear armament raises difficult questions with no clear answers, and we hope that future leaders deal with these issues sensitively and responsibly.


Penina Wein is a sophomore at SCW majoring in Jewish Education and minoring in Psychology, and is a staff writer for Kol Hamevaser.


[i] Guy B. Roberts, “Judaic Sources of Views on the laws of War,” The Naval Law Review 37 (1998): 221-238, at p. 227.

[ii] J.D. Bleich, “Societal Issues,” Contemporary Halakhic Problems, Volume III (New York: KTAV Publishing House, Inc., 1989), 5.

[iii] Rambam, Mishneh Torah, Hilkhot Melakhim 5:1-2.

[iv] Michael Broyde, “Fighting the War and the Peace: Battlefield Ethics, Peace Talks, and Pacifism in the Jewish Tradition,” in War and its Discontents: Pacifism and Quietism in the Abrahamic Traditions, ed. by J. Patout Burns (Washington, D.C.: Georgetown University Press, 1996), 1-30, at p.6

[v] Broyde 6.

[vi] Broyde 12.

[vii] Shev’uot 35b, according to the interpretation of Tosafot, against Rashi and Rashba.

[viii] Broyde 12.

[ix] Immanuel Jakobovits, “Rejoinders,” Tradition: A Journal of Orthodox Jewish Thought 4.2 (1962): 198-205, at p. 202.

[x] Broyde 13.

[xi] Elliot Dorff, “Bombs, Bishops and Rabbis,” in Confronting Omnicide: Jewish Reflections on Weapons of Mass Destruction, ed. by Daniel Landes (Jason Aronson, Inc., 1991), 180-182, at p.180.

[xii] Ibid.

[xiii] Ibid.

[xiv] Rav Moshe Lichtenstein, “The War of Gog U’Magog: The Haftara of Shabbat Chol Ha-moed Sukkot,” available at:

[xv] Academy BJE, “Jews & The Atom Bomb,” available at:

[xvi] PressTV, “Israel’s Dimona Risks Uncovered,” December 13, 2011, available at: