Frequently asked questions: Nuclear Weapons

The use of nuclear weapons would cause catastrophic humanitarian consequences and incalculable human suffering, especially in or near populated areas. It would result in immediate mass casualties and long-term suffering. Survivors face severe injuries, chronic illnesses from radiation exposure and psychological trauma. Medical infrastructure would likely be destroyed, leaving survivors without adequate care. Use of nuclear weapons would trigger mass movements of people and precipitate a public health emergency of vast proportions. The effects would transcend national borders and reverberate globally. Any use of a nuclear weapon would also involve a risk of escalation.

There is no adequate humanitarian response capacity in case of use of nuclear weapons. 

On August 6, 1945, a nuclear bomb was dropped on Hiroshima, instantly killing an estimated 70,000 people. Three days later, on August 9, a second bomb was dropped on Nagasaki, killing 39,000 instantly. By 1950, the death toll from both bombings had risen to approximately 340,000 due to long-term radiation effects. 

The bombings also destroyed most medical infrastructure, leaving survivors without adequate care. In Hiroshima, 92% of nurses and 90% of doctors were killed, and 80% of the medical infrastructure was destroyed. 

The Hiroshima bomb had an explosive yield of about 15 kilotons, what today would be described as a small or “tactical” nuclear weapon.

There are approximately 12,000 nuclear weapons globally, with a combined destructive power of 2,000 megatons – equivalent to 135,000 Hiroshima-sized bombs. Over 9,000 of these weapons are operational, with some on high alert, ready to be launched at a moment's notice. 

The risk of their use, whether intentional or accidental, is growing amid rising geopolitical tensions and ongoing armed conflicts. This risk is exacerbated by strident nuclear rhetoric and threats of use, accelerated modernization of nuclear arsenals, and potentially dangerous technological developments, including automation and AI. Meanwhile, nuclear doctrines are being revised to strengthen the role of nuclear weapons and to lower the threshold for their use.

The ICRC, and the broader Red Cross and Red Crescent Movement, have concluded that it is extremely doubtful that nuclear weapons could ever be used in accordance with the principles and rules of IHL. Any use of nuclear weapons against, in, or near a populated area would violate the principle of distinction, and the prohibitions of indiscriminate and disproportionate attack. Even if used far away from populated areas, the suffering to combatants caused by radiation exposure, and the radiological contamination of the environment and risk of spread of radiation to populated areas, make it extremely doubtful that nuclear weapons could ever be used in accordance with the rules prohibiting the use of weapons of a nature to cause superfluous injury or unnecessary suffering, and the rules for the protection of the natural environment and the civilian population. 

The principles and rules of IHL apply to all means and methods of warfare, including nuclear weapons – even in situations of national self-defence.

For more detailed information, see: The ICRC’s legal and policy position on nuclear weapons

The ICRC, and the broader Red Cross and Red Crescent Movement, have consistently called for the prohibition and elimination of nuclear weapons since witnessing their catastrophic effects in Hiroshima and Nagasaki in 1945. We advocate for their complete elimination as a humanitarian imperative and in compliance with international law. Any use of nuclear weapons would be abhorrent to the principles of humanity and the dictates of public conscience. Any threat to use nuclear weapons is equally abhorrent, as it implies the possibility of actually using them. Total elimination of nuclear weapons is the only way to guarantee they are never used again, and is the aim of both the Nuclear Non-proliferation Treaty (NPT) and the Treaty on the Prohibition of Nuclear Weapons (TPNW). 

For more detailed information, see: The ICRC’s legal and policy position on nuclear weapons

The Treaty on the Prohibition of Nuclear Weapons (TPNW) is the first international agreement of global scope to comprehensively prohibit nuclear weapons, which is an essential step towards their elimination. The TPNW also reinforces the stigma against their proliferation and use. It bans the use, threat of use, development, production, testing and stockpiling of nuclear weapons, and provides pathways for their elimination. The treaty entered into force on 22 January 2021 and represents a historic step towards preventing the catastrophic humanitarian consequences of nuclear weapons. The treaty also includes provisions for assisting people harmed by the use or testing of nuclear weapons and for remediating environmental damage.

The TPNW globalizes the prohibitions that already exist in the five treaties establishing Nuclear Weapon-Free Zones in Latin America and the Caribbean (Tlatelolco Treaty), South Pacific (Rarotonga Treaty), Southeast Asia (Bangkok Treaty), Africa (Pelindaba Treaty) and Central Asia (Semipalatinsk Treaty).

The ICRC and the broader Red Cross and Red Crescent Movement call on all States that have not yet done so to promptly join and faithfully implement the TPNW.

For more detailed information: see View of the ICRC on interpretation of the Treaty on the Prohibition of Nuclear Weapons

As of July 2026, 75 states have ratified the TPNW, and an additional 25 states have signed it. While no nuclear-armed states have joined the treaty, it provides pathways for their eventual adherence, and contributes to delegitimizing and stigmatizing nuclear weapons globally.

• Advocate for states to join the TPNW and support its implementation.
• Raise awareness about the catastrophic humanitarian consequences of any use of nuclear weapons.
• Condemn and stigmatize any threats to use nuclear weapons, and any other rhetoric that erodes the taboo against their use;
• Support organizations working on nuclear disarmament and victim assistance.
• Encourage governments to adopt policies that reduce the role of nuclear weapons in military doctrines and lower the risk of their use.