CNIC Statement: We strongly protest the U.S. and Israeli attacks on Iranian “nuclear facilities.”
On June 13, Israel launched military attacks on multiple targets in Iran, including its “nuclear facilities,” and this was followed by Iranian retaliation. On June 22, the U.S also carried out airstrikes on three of the nuclear facilities in Iran, one of which was a uranium enrichment plant. Regardless of the problems with Iran, this series of attacks violated international law. Furthermore, these were attacks against nuclear facilities that are designated as being for “peaceful purposes,” and are highly dangerous acts. CNIC calls for an immediate end to the attacks and continuation of the ceasefire between the belligerent parties.
Iran owns a large number of “nuclear facilities.” Israel has been claiming that these facilities have been diverted for military use. In fact, Iran’s stockpile of highly enriched uranium has rapidly increased in recent years, and according to a report in May 2025, the country possesses 408.6kg of 60% or more enriched uranium[i]. IAEA defines uranium enriched to 20% or more as highly enriched uranium and set its significant quantity (the amount of nuclear material for which the possibility of manufacturing a nuclear explosive device cannot be excluded) as 25kg[ii]. In addition, although it is possible to manufacture a nuclear weapon using highly enriched uranium, in general, uranium enriched to 90% or more is considered to be weapons-grade uranium.
Highly enriched uranium is used mainly for nuclear weapons, research reactors, and nuclear submarines. In recent times, many research reactors have switched fuel from highly enriched uranium to low-enriched uranium from the perspective of nuclear non-proliferation. While Iran has plans to construct nuclear submarines, this is not feasible with the current Iranian technology. Additionally, although the amount of uranium used to power a nuclear submarine varies depending on power output, in general about 500kg of highly enriched uranium would be used, and for a submarine with small output 100g of highly enriched uranium (in the case of 45% enrichment) would be used.[iii][iv]
The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) recognizes the right of the peaceful use of nuclear energy to all the Parties to the Treaty and the enrichment of uranium is included in this right. Iran has been claiming that their nuclear activities are for peaceful purposes. In fact, although there have been various reports indicating Iran’s moves to develop nuclear weapons, the IAEA has announced that there has been no evidence to support nuclear weapon development activities by Iran. Also on March 26, the Director of National Intelligence reported to the U.S. congress that “the IC (United States Intelligence Community) continues to assess that Iran is not building nuclear weapons and that Supreme Leader Khamenei has not authorized the nuclear weapons program that he suspended in 2003.”[v] [vi] Nevertheless, there is no doubt that Iran’s questionable conduct poses a threat to the security and the stability of the region.
Let us reaffirm the unlawful acts committed by Israel and the U.S. under international law. Article 2(4) of the Charter of the United Nations provides for a general prohibition on the threat and use of force as follows. “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.” Even though Article 42 states that armed force can be used based on a decision made by the Security Council, there has been no such decision in this case. Article 51 allows the exercise of the right of individual or collective self-defense in the event of an armed attack until the Security Council takes necessary measures. This instance, however, involved a preemptive attack by Israel and there is no room to justify such a right.
Article 56 of Additional Protocol I to the Geneva Convention (in which Israel does not participate, and which the U.S. and Iran have signed but not ratified) prohibits attacks on nuclear power plants “if such an attack may cause a dangerous release of force, resulting in severe losses among the civilian population.” However, the facilities that have been allegedly attacked so far are considered to be excluded, since the Arak heavy water reactor was not in operation and, the facilities in Isfahan, Natanz, and Fordow are not nuclear power plants. On the other hand, what is of concern is an attack on Bushehr Nuclear Power Plant, which is in operation. If a missile were to strike a nuclear reactor building, large amounts of radioactive substances would be released into the atmosphere. Even the loss of external power supply caused by attacks on power transmission lines could increase the risk of an accident. These kinds of attacks are naturally subject to prohibitions under the Geneva Convention.
In the process of enrichment, uranium is converted to gaseous uranium hexafluoride. Uranium hexafluoride is relatively heavy gas, and does not cause harmful effects over an extensive area unless a considerable amount is released. If such a release happens within a facility, however, that would be a different story, since the reaction between uranium hexafluoride and water vapor in the air produce hydrogen fluoride, which is extremely harmful to the human body. Also, uranium is known to cause damage to kidney tissue due to its heavy metal toxicity. In terms of radiation exposure, the amount of inhaled uranium that produces an effective dose of 1mSv is 3.4mg in the case of 20% enriched uranium.[vii][viii][ix][x][xi] In the atmosphere, uranium hexafluoride quickly converts to uranium dioxide, in this case producing a more severe exposure dose.
Even if attacks on facilities such as uranium enrichment plants are not prohibited by the treaty, the actions of Israel and the U.S., which might lead to a facile overcoming of the psychological hurdle to launching attacks on civilian nuclear facilities, are undermining the foundation for the “peaceful use” of nuclear energy. In an effort to establish an international norm of not attacking civilian nuclear facilities, past IAEA General Conference resolutions have repeatedly stated that armed attacks and threats to civilian nuclear facilities violate the principal of the Charter of the United Nations, international law, and the IAEA Statute. These efforts are about to go up in smoke due to the Russia-Ukraine war and recent Israeli-U.S. attacks on Iran.
Satellite image analyses and Iranian news reports have suggested that Iran moved its enriched uranium prior to the attack on the enrichment plant. The extent of the damage caused by the U.S. attack on the facilities is still uncertain. However, these attacks by Israel and the U.S. are dangerous actions that could lead Iran, which has thus far shown restraint, to move toward nuclear armament. At 7:02 a.m. (JST) on June 24, U.S. President Donald Trump announced on his social media that Iran and Israel had agreed to a ceasefire.[xii] It was reported that Iran would initiate a ceasefire six hours after the announcement and Israel would implement its ceasefire 12 hours from the time of the announcement, and that the war would end a further 12 hours later (around 13:00 on June 25 JST).[xiii] Although the situation is fluid and hard to predict, we would like to urge the Japanese Government to work together with the international community to call for restraint from all the countries concerned.
[i] IAEA. 2025. Verification and monitoring in the Islamic Republic of Iran in light of United Nations Security Council resolution 2231 (2015). Accessed June 24 2025. www.iaea.org/sites/default/files/25/06/gov2025-24.pdf
[ii] IAEA. 2022. IAEA Safeguards Glossary 2022 edition. Accessed June 24 2025. www.iaea.org/publications/15176/iaea-safeguards-glossary
[iii] Hanlon, B. P. 2015. Validation of the Use of Low Enriched Uranium as a Replacement for Highly Enriched Uranium in US Submarine Reactors. Accessed June 24 2025. dspace.mit.edu/bitstream/handle/1721.1/103656/953286533-MIT.pdf
[iv]Heinonen, O. 2012. Nuclear Submarine Program Surfaces in Iran. The Belfer Center for Science and International Affairs. Accessed June 24 2025. www.belfercenter.org/publication/nuclear-submarine-program-surfaces-iran
[v] Office of the Director of National Intelligence. 2025. DNI Gabbard Opening Statement as Delivered to the HPSCI on the 2025 Annual Threat Assessment of the U.S. Intelligence Community. Office of the Director of National Intelligence. Accessed June 25, 2025. www.dni.gov/index.php/newsroom/congressional-testimonies/congressional-testimonies-2025/4061-ata-hpsci-opening-statement-as-delivered
[vi] However according to the report, the Director of National Intelligence reversed her statement on June 21 that the country could build nuclear weapons within weeks.
Santos, S. F. 2025. Tulsi Gabbard now says Iran could produce nuclear weapon “within weeks.” BBC. Accessed June 25, 2025. www.bbc.com/news/articles/c056zqn6vvyo
[vii] Chemical toxicity and regulations of uranium hexafluoride (In Japanese) 2014. ATOMICA. Accessed June 24 2025. atomica.jaea.go.jp/data/detail/dat_detail_11-02-03-03.html
[viii] IAEA. 1983. General Conference resolution GC(27)/RES/407. Accessed June 24 2025. www.iaea.org/sites/default/files/gc/gc27res-407_en.pdf
[ix]IAEA. 1985. General Conference resolution GC(29)/RES/444. Accessed June 24 2025. www.iaea.org/sites/default/files/gc/gc29res-444_en.pdf
[x]IAEA. 1987. General Conference resolution GC(31)/RES/475. Accessed June 24 2025. www.iaea.org/sites/default/files/gc/gc31res-475_en.pdf
[xi]IAEA. 1990. General Conference resolution GC(34)/RES/533. Accessed June 24 2025. www.iaea.org/sites/default/files/gc/gc34res-533_en.pdf
[xii] Trump, J. D. 2025. Truth social. Jun 24, 2025, 7:02 AM. Accessed June 24 2025. truthsocial.com/@realDonaldTrump/posts/114734934153569653
[xiii] Cook, S., Joe, W., Fin, D. G., & Brian, D. (2025, June 24). Trump announces Israel-Iran ceasefire. CBS News. Accessed June 24 2025.www.cbsnews.com/news/trump-israel-iran-ceasefire/
