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Iran Update, December 22, 2025

Iran is likely prioritizing ballistic missile production due to both organizational inertia within the Iranian defense apparatus and the need to restore deterrence in what it views as an ongoing war with Israel. The reconstitution appears to be an effort to restore deterrence against Israeli attack, though a reconstituted ballistic missile program could be used to attack Israel. One former senior Iranian official has doubled down on investment in the ballistic missile program after the Israel-Iran War to “restore deterrence,” while a current senior official advocated for new technical improvements to the missiles, for example.[1] These officials probably calculate that more and higher-quality missiles are needed to penetrate Israeli defenses, given the effectiveness of Israeli ballistic missile interceptors and the decreasing Israeli interceptor stockpile. The reconstitution of Iran's ballistic missile capabilities is nonetheless increasing anxiety in Israel over the quantity of missiles Iran now possesses (see below).

An Israeli journalist reported on December 9 that Iran had reconstituted its missile stockpile to around 2,000 “heavy” ballistic missiles, which presumably refers to medium-range ballistic missiles capable of striking Israel. This rapid reconstitution indicates that Israel either failed to destroy all of Iran's planetary mixers or that Iran has acquired or built new planetary mixers used to produce solid fuel ballistic missiles. The United States intercepted a shipment with components for Iran's ballistic missile program, which could have included mixers, in the Indian Ocean in November 2025 (more on this incident below). Iran is reportedly prioritizing the rapid restoration of its ballistic missile production capabilities over other defense priorities. Iran has begun rebuilding the Parchin and Shahroud missile production facilities, which Israel damaged during the Israel-Iran War, and reconstructing buildings at these sites that previously housed planetary mixers.[2] Planetary mixers are essential for turning a chemical precursor of solid fuel, sodium percolate, into ballistic missile fuel.[3] Israel destroyed Iran's planetary mixers in October 2024, and Western media assessed in September 2025 that Iran still did not have the necessary planetary mixers to produce solid missile fuel.[4] Western diplomats also told Israeli media on December 8 that Iran is using older manufacturing methods to continue producing ballistic missiles, which may refer to the less efficient “trough-type mixers” that can also produce solid fuel.[5]

Iranian defense officials view ballistic missiles as a critical piece of their defense strategy, and a hypothetical Iranian decision to abandon the ballistic missile program would be antithetical to the way that Iranian commanders view their capabilities and relative strengths. Iran's decision to prioritize ballistic missiles after their failure to penetrate Israeli defenses during the Iran-Israel War in June 2025 may appear unwise to Western observers, but this ignores the primacy with which Iranian officials view ballistic missiles in their defense strategy. Iranian officials would probably find it extremely difficult to come to a personal conclusion and then convince the bureaucracy to conclude that ballistic missiles must be abandoned, given that most of Iran's defense community has long viewed and continues to view ballistic missiles as a critical element of their defense strategy both now and in the future. Missiles, in addition to Iran's Axis of Resistance, have long acted as the central pillar of Iran's regional defense strategy, and Iranian officials have long considered the ballistic missile program to be a crucial deterrent to Israel and the United States.

Senior Iranian officials have continued to laud Iran's missile capabilities as an essential piece of Iranian defense strategy, even after the Israel-Iran War.[6] A former IRGC Navy commander said that the missile program contributed to Iran's ”success” during the war.[7] Former Islamic Revolutionary Guards Corps (IRGC) Commander Mohammad Ali Jafari argued in October 2025 that Iran's missile program is its main form of deterrence and that Iran deliberately prioritized developing its missile and drone capabilities over its air and ground forces to counter the superior capabilities of the United States and Israel.[8] Another senior official illustrated the need for more investment in the program by calling for various technical improvements to the missiles to improve their ability to penetrate ballistic missile defenses.[9] Iranian military officials would need to garner enormous political backing in order to alter a pillar of Iranian defense strategy for decades, and so far, no sizeable group of officials has challenged the importance of the missile program in the public discourse.

Iran's ability to produce ballistic missiles at scale only six months after the end of the Israel-Iran War in June 2025 is causing Israeli anxieties over Iranian capabilities and intent to attack Israel. Israeli Prime Minister Benjamin Netanyahu is planning to brief US President Donald Trump on the United States’ options for joining or assisting future Israeli attacks on Iranian ballistic missile sites during Netanyahu's upcoming visit to the United States on December 29, according to an unspecified source and four former US officials.[10] Israeli officials reportedly view Iran's efforts to rebuild ballistic missile production facilities and repair air defense systems as “more immediate concerns” than Iran reconstituting its nuclear enrichment sites.[11] Axios reported on December 21 that Israeli military intelligence and Mossad do not assess that the pace at which Iran is rebuilding its ballistic missile capabilities necessitates “urgency to take military action” within the next two to three months. The Israeli sources stressed that Iran's ballistic missiles could “become a more urgent issue later in the year,” presumably referring to late 2026.[12] Israeli media highlighted Israel's threat perception and noted that the Iranian regime may only need between one and two years to acquire enough ballistic missiles to overwhelm Israeli air defenses. This calculation is based on Iran reaching a production rate of about 300 ballistic missiles per month.[13] The Wall Street Journal reported in June 2025, during the war, that Israel was “running low on defensive Arrow interceptors.”[14] Defensive Arrow interceptors enable Israel to counter long-range ballistic missiles.[15] Israel used 52.3 percent of its interceptor stockpile during the war, according to the Jewish Institute for National Security of America (JINSA).[16]

Reports about a possible IRGC Aerospace Force missile exercise coordinated across multiple bases in Iran have also contributed to Israeli fears of a rising Iranian ballistic missile threat.[17] IRGC-affiliated media reported on December 22 that the IRGC Aerospace Force launched missiles as part of its missile exercise in unspecified locations in five provinces.[18] The exercise reportedly spanned across Khorramabad, Lorestan Province, Mahabad, West Azerbaijan Province, Mashhad, Khorasan Razavi Province, Tehran Province, and Esfahan Province.[19] Iranian media did not provide any more specific details on the exercise, such as the types of missiles launched.

The regime may have been rehearsing the synchronization and coordination of large scale missile strikes from bases spread across the country through the exercise. Iran's ability to launch coordinated, large scale missile attacks targeting Israel during the June 2025 war grew constrained as Israel destroyed Iranian missile launchers across different regions of Iran, according to an Israeli Army Radio correspondent in June 2025.[20] Unspecified sources told anti-Iranian regime media on December 20 that Western intelligence agencies detected “unusual” IRGC Aerospace Force activity, including irregular drone, missile, and air defense units’ command-and-control signals, deployments, and logistical movements.[21] These activities, if accurate, would also be consistent with Iranian efforts to rehearse the synchronized deployments of missile, drone, and air defense assets. Exercises to improve coordination and synchronization do not necessarily need to involve missile launches.

The regime may be attempting to obscure details about the exercise and therefore downplay the extent to which the IRGC may be preparing for future conflict. Iranian state media denied the IRGC-affiliated news report on the IRGC exercise, calling it “not accurate.”[22] Another Iranian media outlet affiliated with the Supreme Leader's representative to the Defense Council circulated a news report about the exercise before later removing the article.

IDF Chief of Staff Lieutenant General Eyal Zamir warned US Central Command (CENTCOM) Commander Admiral Brad Cooper on December 20 that the IRGC Aerospace Force missile exercise and other operational steps could be “cover for a surprise attack“ on Israel.[23] Zamir referred to an IRGC exercise that “began several days ago.“[24] Netanyahu also stated on December 22 that Israel is “aware that Iran is conducting military exercises: and “making the necessary preparations,” warning that any attacks on Israel will be met with a “very harsh response.”[25] An unspecified US source told Axios on December 22 that US intelligence agencies have no indication that Iran is preparing for an attack.[26]

The People's Republic of China (PRC) continues to support Iranian missile production. An Israeli Army Radio correspondent reported on December 22 that a shipment of planetary mixers was expected to travel from the PRC to Iran in recent weeks but that the “shipment ultimately did not reach its destination,” citing Western intelligence sources.[27] US officials told the Wall Street Journal on December 12 that US special forces recently boarded and seized a vessel in the Indian Ocean carrying PRC-made components destined for Iran's missile program.[28] It is possible that this vessel was carrying the planetary mixers shipment that the Israeli Army Radio correspondent reported. Iran currently lacks planetary mixers. The PRC has previously helped Iran rebuild its ballistic missile program by supplying Iran with sodium perchlorate, which is a chemical precursor for solid missile propellant. The PRC previously sent two shipments of sodium perchlorate to Iran in February and June 2025, and European intelligence sources have been tracking a further 10 to 12 shipments following the Israel-Iran War.[29]

Iran may retaliate against the United States’ attempted seizure of an Iranian-linked tanker in the Caribbean Sea with disruptive activity in the Persian Gulf.[30] US authorities obtained a seizure warrant for the Bella 1 tanker on December 21 due to the vessel's “previous involvement in the Iranian oil trade.”[31] The Bella 1 loaded oil in August 2025 at Kharg Island, which is Iran's primary oil export hub, and later offloaded its cargo to another tanker near Oman before continuing to the Caribbean Sea.[32] The United States has not seized the Bella 1 as of this writing. Senior Iranian officials have threatened to close the Strait of Hormuz if the United States and its allies seize Iranian exports in recent months.[33] The IRGC also conducted various combat operations in the Persian Gulf as part of their annual naval exercise in the Persian Gulf in early December as a warning to its adversaries that Iran will confront any “miscalculations” with “a decisive response.”[34] The IRGC Navy also named this year's exercise after deceased IRGC Navy commander Mohammad Nazeri, who was reportedly involved in the seizure of two US patrol boats and 10 US personnel in the Persian Gulf in January 2016.[35] Iran responded to US seizures of Iranian weapons shipments under US President Donald Trump's first maximum pressure campaign in 2019 by threatening international shipping, including by seizing a British oil tanker, harassing vessels transiting the Strait of Hormuz, and conducting an attack targeting Saudi oil facilities.[36]

https://understandingwar.org/research/middle-east/iran-update-december-22-2025/