China’s KD-21 air-launched ballistic missile (ALBM) has quietly entered service, adding a potent new threat to US aircraft carriers, air bases and exposed parked aircraft across the Western Pacific.
Recent images obtained by The War Zone (TWZ) show frontline People’s Liberation Army Air Force (PLAAF) H-6K bombers armed with KD-21 missiles, confirming the weapon’s operational status.
First revealed during Airshow China 2022 in Zhuhai, the KD-21 represents a significant step in China’s anti-access/area-denial (A2/AD) strategy to counter US power projection across the Indo-Pacific.
Analysts immediately recognized the missile’s strategic potential, with many likening it to Russia’s Kinzhal ALBM. While its precise role—whether tailored more for anti-ship or land-attack missions—remains ambiguous, the KD-21’s similarity to the CM-401 anti-ship ballistic missile suggests it may be capable of both.
Observers noted that the missile was carried by a bomber from the PLAAF’s 10th Bomber Division based in Anqing, Anhui Province, under the Eastern Theater Command, suggesting its potential employment in operations targeting Taiwan, Japan and beyond.
The KD-21’s reported hypersonic speed and maneuverability make it particularly challenging for US air defense systems. Its pairing with the H-6K, a modernized variant of China’s Cold War-era bomber, offers China significantly extended reach.
Equipped with more efficient turbofan engines and capable of in-flight refueling, the H-6K allows the KD-21 to threaten targets well beyond the First Island Chain, possibly reaching as far as Guam, where the US maintains significant military assets.
By integrating the KD-21 with an expanding arsenal of traditional ballistic missiles, cruise missiles and unmanned aerial systems, China aims to challenge and defeat US and allied defenses.
The operational deployment of ALBMs, such as the KD-21, underscores China’s efforts to diversify its missile force and enhance its strike capabilities against key assets throughout the Western Pacific.
ALBMs offer several advantages over cruise missiles. A 2019 Federation of American Scientists (FAS) report by Eugene Saad and Adam Mount explains that with their higher speeds, ALBMs enable rapid strikes, thereby compressing the time available for enemy forces to react.
Moreover, their deployment from mobile aerial platforms allows them to launch from unpredictable vectors, thereby bypassing air defense systems that are optimized for traditional ground-based threats.
Saad and Mount also emphasize that ALBMs enhance the survivability of delivery platforms. Unlike fixed missile sites, bomber aircraft can disperse, remain airborne or operate from concealed positions, reducing their vulnerability to preemptive strikes.
However, these advantages are tempered by operational risks. A 2018 RAND report by Derek Grossman and colleagues highlights the persistent vulnerabilities of the H-6K bomber, particularly during overwater missions near contested airspaces, such as those surrounding Taiwan and the Japanese archipelago.
While the KD-21 may extend the bomber’s standoff range, allowing it to fire from safer distances, the H-6K remains susceptible to interception by US and allied air combat patrols equipped with advanced fighters and air defense networks. These risks could complicate Chinese strike operations in an actual conflict.
Still, the PLAAF has steadily modernized its bomber force and doctrine. A 2022 report by the China Aerospace Studies Institute (CASI) describes the H-6K as the backbone of China’s long-range conventional strike capabilities.
The bomber’s upgraded engines allow it to project power deep into the Western Pacific, and its integration within the PLAAF’s preserved division-regiment structure provides the organizational resilience for sustained operations.
CASI notes that regiment-level training and modernization efforts have ensured the H-6K’s relevance in China’s evolving regional deterrence posture. Meanwhile, the KD-21’s speed, maneuverability, and precision make it particularly suited for disabling critical US military infrastructure.
In a 2019 National Defense Magazine article, Jon Harper and Tom Callender discuss how bomber-launched hypersonic missiles, such as the KD-21, could exceed Mach 5 and maneuver unpredictably during terminal phases to evade US defenses.
Callender notes that such missiles can exploit gaps in high- and low-altitude coverage, posing a threat to carriers even at long ranges. While John Richardson has downplayed the vulnerability of US carriers, citing a combination of operational concepts and defensive systems offsetting the threat, others, including Michael Griffin and Samuel Greaves, stress the urgency of developing countermeasures.
Their recommendations include novel interceptors, space-based sensors for continuous tracking and advanced technologies such as railgun projectiles to improve missile defense capabilities.
Beyond carriers, US airbases in the Western Pacific face acute risks from China’s expanding missile arsenal. A 2024 Stimson Center report by Kelly Grieco and others outlines how China could cripple US airpower projection by targeting runways with ballistic and cruise missiles carrying runway-penetrating submunitions.
Grieco and others estimate that such attacks could render fighter runways in Japan unusable for up to 12 days and Guam’s for at least two, severely disrupting the tempo of US military operations in a conflict scenario.
Moreover, tanker operations—vital for sustaining airpower over vast distances—could be denied for weeks, particularly in Japan, exacerbating the challenge of generating sorties during the critical opening phase of a conflict.
These vulnerabilities have been compounded by relative underinvestment in the hardening of US base and other facilities. A 2025 Hudson Institute report by Thomas Shugart III and Timothy Walton reveals that, despite recognizing the missile threat for over a decade, the US has constructed only two hardened aircraft shelters (HAS) and 41 non-hardened shelters at airfields within 1,000 nautical miles of Taiwan.
In stark contrast, China has built more than 3,000 hardened shelters. The report further notes that key US bases in Guam and the Philippines have no HAS at all, leaving aircraft, fuel stores and maintenance facilities exposed to even small-scale missile salvos. Shugart and Walton conclude that these shortfalls leave US air assets vulnerable to initial strikes, limiting their capacity to sustain operations during a significant contingency with China.
The KD-21’s introduction into China’s operational missile inventory signals more than just the fielding of another precision strike weapon—it underscores China’s commitment to recalibrating the military balance of power in the Western Pacific in its favor.
As China refines its ability to penetrate US defenses from the flight deck to the flight line, the risks for US and allied forces will only grow more acute over time.
