U.S. Facing Defensive Weapon Shortage vs. Iran Lacking Offensive Arms [Yang Nakkyu's Defence Club]

by Yang Nakgyu

Published 04 Mar.2026 08:01(KST)

Updated 04 Mar.2026 17:27(KST)

U.S. May Deploy U.S. Forces Korea to Middle East Amid Shortage of Defensive Weapons
Iran Shares Missile Technology with North Korea... Likely to Seek Help from Ally

There are projections that the United States may request assistance from the South Korean government to replenish its depleted defensive weapons. Although President Donald Trump has signaled the potential for prolonged military operations against Iran, the US currently lacks sufficient weapons to counter Iran's attacks.

Plumes of smoke rise after a US-Israel military strike in Tehran, Iran. AP Photo The Associated Press

According to military officials on March 4, the US military considers the Terminal High Altitude Area Defense (THAAD) system and SM-3 surface-to-air missiles as core defensive assets for intercepting enemy ballistic missiles. The THAAD system is deployed at ground bases, while the SM-3 is installed on destroyers. Both are key weapon systems for countering Iranian retaliation.

However, after the unprecedented rate at which air defense missiles were expended during the 12-Day War between Iran and Israel in June last year, the United States has not been able to replenish its stockpiles. Up to 150 THAAD missiles were used for Israel’s defense. Since the THAAD system began operations in 2010, the total number of THAAD missiles secured by the US military remains under 650. It is also reported that more than 80 SM-3 missiles, which can intercept ballistic missiles outside the atmosphere when launched from destroyers, have been used up.

The US Has Already Exhausted Defense Weapons such as THAAD and SM-3

The situation is equally serious for other key interceptor missiles with shorter ranges than the SM-3, such as the SM-2 and SM-6, which are used for terminal phase interception. Brendan McLane, Commander of Surface Forces for the US Pacific Fleet, disclosed that about 200 SM-2 and SM-6 missiles were used during operations against the Houthi rebels in the Red Sea through January 2025. In fact, senior US military officials are said to have reported to President Trump that with such depleted arsenals, it would be difficult to conduct prolonged military operations against Iran.

The replenishment process is slow due to the high cost of interceptor missiles. The US Department of Defense plans to procure 37 THAAD missiles for USD 840 million and 12 SM-3 missiles for USD 445 million in the fiscal year 2026. The unit price is USD 23 million (approximately KRW 3.31 billion) and USD 37 million (approximately KRW 5.34 billion), respectively.

Possibility of Deploying USFK’s THAAD and Patriot Air Defense Assets

If the United States cannot replenish its defensive weapons, it will have no choice but to request help from the South Korean government. There are predictions that US military assets and personnel currently stationed in South Korea could be relocated to the Middle East. Experts believe assets such as the Patriot and THAAD air defense systems of the US Forces Korea, as well as surveillance and reconnaissance assets like the MQ-9 Reaper drone, which was permanently deployed to the Gunsan base in South Korea last year, could be among those redeployed.

In June last year, ahead of the "Midnight Hammer" operation to strike Iranian nuclear facilities, the US military temporarily deployed three out of the eight Patriot batteries from US Forces Korea to the Middle East to prepare for potential Iranian retaliation. The Patriot batteries and the 500 personnel assigned to the Middle East at that time returned to South Korea in October last year.

The Terminal High Altitude Area Defense (THAAD) system was deployed in Seongju, Gyeongbuk in 2017. Photo by Yonhap News Agency

Shin Jongwoo, Secretary General of the Korea Defense Security Forum, commented, "If the airstrikes become prolonged, the United States will likely attempt to utilize USFK’s forces and assets." The South Korean government has also mentioned the possibility of support. A government official stated, "There is always ongoing consultation between South Korea and the United States regarding the operation of USFK assets. We are gathering opinions through discussions to ensure that the combined defense posture is not compromised." On March 2, Defense Minister Ahn Kyubaek had a phone call with US Department of Defense Deputy Under Secretary for Policy Elbridge Colby at his request, during which the South Korean side was briefed on the US position regarding military operations against Iran, according to the Ministry of National Defense.

Indirect Ammunition Support Like in Ukraine

There is also a significant possibility of ammunition support. In the early stages of the war in Ukraine, the South Korean military provided the United States with war reserve stocks for the Korean Peninsula (WRSA-K), including 550,000 rounds of 155mm artillery shells, at the US's request. WRSA-K refers to ammunition brought to South Korea by the United States over a five-year period starting in 1974 to prepare for wartime situations on the Korean Peninsula. Since the South Korean government retains ownership of WRSA-K ammunition, the US cannot provide these shells to Ukraine without South Korea’s consent. However, the WRSA-K shells were not sent directly to Ukraine; instead, they were used to replenish US military reserves, and the US then provided its own existing shells to Ukraine. Subsequently, the US entered into contracts with domestic defense firms producing shells and compensated the South Korean military in return.

Neighboring Countries Likely to Request Additional Korean Defense Exports, including Cheongung

There is an expectation that neighboring countries will also increase their requests for defensive weapons. It has been reported that the domestically produced Cheongung-II air defense system deployed in the United Arab Emirates (UAE) intercepted missiles launched by Iran. After the UAE military authorities signed a contract in 2022 with South Korea’s LIG Nex1, Hanwha Systems, and Hanwha Aerospace to introduce 10 Cheongung-II batteries, two batteries have been deployed in active service to date.

The Latest Surface-to-Air Guided Weapon 'Chun-gung' to Replace Hawk

When Iran, having been attacked by the United States and Israel, launched missile attacks on US military bases in neighboring countries, the Cheongung-II batteries deployed in the UAE reportedly operated alongside US-made Patriot and Israeli-made Arrow air defense systems to intercept Iranian missiles. The Cheongung-II is a medium-range and medium- to high-altitude surface-to-air interception system developed to counter both ballistic missile and aircraft attacks simultaneously, and is known as the "Korean Patriot." Each Cheongung-II battery consists of four launchers, as well as a radar and engagement control center. This is reportedly the first time that a domestically produced Korean air defense system exported overseas has been used in an actual combat situation.

If Israel Exhausts Its Missiles, It May Turn to North Korea

On the other hand, if Iran's supply of offensive weapons dwindles, it may turn to North Korea for assistance. Iran is currently estimated to possess around 2,000 ballistic missiles. However, with the United States deploying its most advanced assets to carry out concentrated strikes on more than 1,000 targets within Iran, there are significant predictions that Iran’s ballistic missile launchers could be neutralized first. In fact, the Israeli military announced on March 1 that it had destroyed about 200 of Iran’s ballistic missile launchers and disabled dozens more through airstrikes conducted since June last year. This accounts for approximately half of Iran’s current launchers.

Iran and North Korea Have an Alliance Involving Missile Technology Sharing

Iran and North Korea have already been sharing missile technology. In a report on Iran's military capabilities released in November 2019, the US Department of Defense’s Defense Intelligence Agency (DIA) analyzed that North Korean technology is linked to Iran’s weapon systems, including ballistic missiles. The report specifically evaluated that Iran’s medium-range ballistic missiles (MRBMs) were influenced by North Korean missile technology. For example, Iran’s main medium-range ballistic missile, the liquid-fueled Shahab-3, is known to be based on North Korea’s Nodong missile. The Khorramshahr missile, which Iran has produced since 2017, is also described in the report as being connected to North Korea’s Musudan missile technology. The report noted that Iran possesses more advanced technology than North Korea in the field of solid-fuel missiles, with the Fateh series of solid-fueled short-range ballistic missiles cited as a prime example.

Some analysts say it would be difficult for North Korea to provide direct missile support to Iran. A government official commented, "Just as it was challenging to supply missiles to Russia, finding a way to provide large quantities is not easy. However, since technology has been shared, if Iran requests assistance, we could consider the option of indirect support."