2026.06.14
La DGA commande le développement du missile hypersonique ASN4G à MBDA
La Direction générale de l’armement (DGA) a notifié, le 2 juin 2026 à MBDA, l’accord cadre de réalisation et le marché de développement du missile Air-Sol nucléaire de quatrième génération (ASN4G). Sa mise en service interviendra à l’horizon 2035. Il sera mis en œuvre à la fois par les Forces...www.defense.gouv.fr
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France’s Hypersonic Leap: Ensuring the Longevity of Nuclear Deterrence
[🇬🇧] France’s Hypersonic Leap: Ensuring the Longevity of Nuclear Deterrence
On 10 June 2026, the DGA announced the order for the development of the Air-to-Surface Nuclear 4th Generation (ASN4G) hypersonic cruise missile, which will equip the RAFALE B and M fighter-bombers at the F5 standard of the Strategic Air Forces (FAS) and the Naval Nuclear Air Force (FANu) by 2035.
letstalkdeterrence.substack.com
by Etienne Marcuz
On 10 June 2026, the DGA announced the order for the development of the Air-to-Surface Nuclear 4th Generation (ASN4G) hypersonic cruise missile, which will equip the RAFALE B and M fighter-bombers at the F5 standard of the Strategic Air Forces (FAS) and the Naval Nuclear Air Force (FANu) by 2035. The communiqué, though laconic, was illustrated with a low-resolution photo showing the launch of a previously unknown object, presented as the THEMIS demonstrator. It is therefore understood that this demonstrator prefigures the future operational missile, and that the results of the test firing(s) were deemed sufficiently satisfactory to launch the final development of the ASN4G, which will be a true game-changing weapon.
The Permanent Race for Velocity
French nuclear deterrence is built over the very long term. When a weapon system enters service, research and development work on its successor is often already underway for several years, to anticipate any evolution in adversary defenses and to ensure that French strategic forces will always be able to penetrate the most sophisticated anti-access/area denial systems to accomplish their mission.The ASN4G is a case in point. This missile is intended to replace the supersonic ASMPA-R cruise missile, which has been operated by the FAS since 2023 and by the FANu since 2025. However, the first studies on the ASN4G began a decade earlier, with the initial objective of determining whether stealth or hypersonic speed offered the best probabilities of penetration—and thus of mission success. This question is far from trivial, and two schools of thought can be observed in this field.
Velocity vs. Stealth
A reference for many Western armies, the Anglo-Saxons (United States/United Kingdom) rely on stealth, both for platforms (combat aircraft) and vectors (missiles carrying military payloads). This is illustrated, for example, by the B-21 RAIDER stealth bomber and the future subsonic stealthy LRSO (Long-Range Stand-Off) cruise missile, which will take over from another subsonic cruise missile, the AGM-86B. On the British side, the replacement for the STORM SHADOW cruise missile will be MBDA’s STRATUS-LO, also a subsonic stealth missile.In France, the choice of velocity is observed from both an operational and technological perspective. Operationally, because the nuclear strike by the FAS and FANu consists of penetrating enemy territory at very low altitude and very high speed, with the aim of blending into the terrain to remain out of radar sight. On the vector side, the ASMPA-R is the latest in a lineage that began in the 1980s with the ASMP, followed by the ASMPA. Its exact speed is undetermined but is widely believed to be supersonic (> Mach 2 or even 3), depending in particular on the flight profile (altitude).
The decision to continue down this path with the ASN4G was not made out of conservatism. It is the result of in-depth studies by the DGA and industry, which simulated multiple engagement scenarios against the most demanding defenses, before concluding that a hypersonic cruise missile was the most likely to reach a heavily defended target.
The Russo-Ukrainian Conflict: A Proxy Testing Ground
It is worth noting that this choice is already being validated in real-world conditions by the war in Ukraine. The near-daily waves of multi-vector Russian attacks against Ukrainian territory allow for the evaluation of the penetration probabilities of each type of weapon:- “Attack drones” (in reality, very slow subsonic cruise missiles) such as the GERAN;
- Subsonic cruise missiles like the Kh-101 and KALIBR;
- Supersonic and hypersonic cruise missiles such as the Kh-22/32, ONYX, and TSIRKON;
- Maneuvering ballistic missiles like the ISKANDER and KINZHAL.
It is possible to exclude “attack drones” for a nuclear mission due to their very low survivability. Their main purpose is to saturate defenses. Carrying a nuclear payload is therefore unthinkable. The same issue seems to arise for subsonic cruise missiles like the Kh-101 and KALIBR, most of which are shot down far from their target. Videos regularly show F-16s chasing and shooting down these missiles over uninhabited areas. Yet, the Kh-101 is the conventional payload version of the Kh-102, a strategic weapon designed to deliver nuclear strikes deep into U.S. territory in the event of total war.
Things become far more complicated for Ukrainian air defenses when fast missiles come into play. The interception rate then drops drastically, even for “merely” supersonic missiles like the ONYX or Kh-22/32. The reduced flight time and maneuvering capability of these vectors require both extreme responsiveness from the defense and interceptors capable of significant maneuvering themselves. Indeed, an interceptor (missile or aircraft) is always sent not directly toward the missile to be intercepted, but toward a meeting point determined by the target’s velocity vector (speed/acceleration/direction). If the target maneuvers, a new meeting point must be calculated and reached. For a subsonic system, this is not too problematic, as the distance it travels between detection and interception is often small. This is far more challenging for fast-moving targets. Combined with the fact that some systems, such as the ISKANDER, KINZHAL, or TSIRKON, operate outside the range of defense systems for much of their flight, this explains the “success” of Russian strikes involving these systems. Only the most capable—and therefore most expensive—air defense systems, such as the PATRIOT or, to a certain extent, the SAMP/T, have a chance of intercepting them, often at the cost of multiple interceptors per incoming vector.
The End of Subsonic Nuclear Cruise Missiles?
Does the low ability of subsonic cruise missiles to penetrate defenses in Ukraine mean their end as nuclear vectors? No.To understand this, it is necessary to recognize that French nuclear operations differ significantly from those of Russia or the United States. First, the size of the French arsenal is incomparable to that of the two main nuclear powers on the planet, making it necessary to optimize resources to the maximum and thus ensure a very high probability of success for each vector fired. Additionally, France’s conventional forces are also limited, and without the help of allies, they would not allow for extensive shaping of the operational theater prior to a nuclear strike, as the United States might do by neutralizing air defense and missile defense systems over a wide area. Thus, the United States can afford to have vectors that are sometimes less sophisticated, relying on stealth platforms such as the F-35A or B-2A, which are themselves part of a vast network-centric system.
Furthermore, subsonic nuclear cruise missiles like the Russian Kh-102 or the U.S. AGM-86B are strategic weapons and are likely primarily intended for use in the event of total war, in coordination with other weapons such as intercontinental ballistic missiles (ICBMs) or submarine-launched ballistic missiles (SLBMs). In a massive attack, strike plans are designed and sequenced to ensure that a maximum number of weapons reach their targets. Consequently, the most penetrative weapons would pave the way for the more vulnerable ones by neutralizing adversary defenses—radars, airfields, etc. Once the adversary’s territory is devastated by hundreds of nuclear detonations from ballistic missiles and cruise missiles, even subsonic cruise missiles would likely have little trouble reaching their now largely undefended targets. This will be all the more true with the arrival of the U.S. LRSO, whose stealth will significantly enhance its penetration capabilities.
For France, the logic is all the more different because the airborne nuclear component (CNA), which deploys the ASMPA-R and, in the future, the ASN4G, is the privileged—but not exclusive—instrument of the warning strike. As a reminder, this strike is intended to signal to the adversary that the conflict has changed in nature and is now considered an existential threat to France. It aims to demonstrate the resolve of the highest political authority to use nuclear weapons to defend its vital interests. The choice of target(s)—military or otherwise, near the front line or deep in adversary territory—is made by the President of the Republic. There is no question here of mass strikes or prolonged suppression of defenses. The ability to penetrate swiftly to the launch point(s) of the missile(s) is required, which must then be capable of overcoming the most hardened defenses, which have not been neutralized beforehand.
A Game-Changing Weapon
This is why the DGA, ONERA, and the entire French defense industrial and technological base have been working continuously since the 1980s to increase the velocity and performance of the airborne vector for the FAS and FANu.The ASN4G will be the latest in a series of high-velocity vectors. However, whereas the ASMPA-R is a derivative of the ASMPA, itself derived from the ASMP, the ASN4G is a technological breakthrough weapon whose performance will be incomparable to that of its predecessor:
- Its range will be at least doubled, reaching 1,000 km (whereas the ASMPA-R’s is estimated at ~500 km, or even less depending on the chosen flight profile);
- Its speed will also be doubled, reaching hypersonic speeds (> Mach 5) rather than supersonic (> Mach 2/3);
- Its cruising altitude will be higher (> 20,000 m), keeping it out of range of a significant portion of defense systems.
The THEMIS Demonstrator
While the first work on the ASN4G dates back to at least 2014, very little information was previously available on the architecture chosen for this system, which must meet multiple constraints. In addition to penetration performance, it must also be capable of being carried under the belly of the FAS’s RAFALE B, as well as being able to withstand a catapult launch from an FANu RAFALE M from the future nuclear aircraft carrier “France Libre,” or even from the Charles de Gaulle. This implies enormous constraints in terms of size and weight, as the RAFALE is a relatively light, short aircraft with limited ground clearance. It is worth noting that the same issue arises with the air-launched version of the future conventional ballistic missile being developed by ArianeGroup.The DGA communiqué published on June 11, announcing the order for the development of the ASN4G, was unexpectedly illustrated with a photo showing a previously unknown system, presented as the THEMIS demonstrator. Unfortunately, no additional information has leaked about the flight of this demonstrator, whether regarding the date and location of the event or the results obtained.
To get an idea of how such a test might unfold, it is possible to refer to the tests of the U.S. X-51A hypersonic cruise missile demonstrator. The United States has the enormous advantage of being very transparent about tests of their technological demonstrators, unlike France, which is much more discreet. The U.S. demonstrator was dropped by a B-52H strategic bomber at an altitude of about 15,000 m, before being propelled to about 21,000 m by a single booster at hypersonic speed. A scramjet engine would then take over to maintain hypersonic cruise speed for several minutes. The X-51A flew four times between 2010 and 2013, with varying success, but the last test allowed it to cover more than 420 km at a maximum speed of Mach 5.1, even though its booster had only accelerated it to Mach 4.8.
While the X-51A and THEMIS likely share similarities, the image released in the DGA communiqué, although of poor quality, reveals architectural choices that are clearly different.
The THEMIS demonstrator is shown in the acceleration phase, propelled by two lateral boosters positioned at the rear of the missile’s fuselage. This likely helps limit the overall length of the system, unlike the single rear booster of the X-51A. The missile itself appears to be equipped with one or two vertical fins at the rear of the fuselage, as well as canard fins at the front. It is difficult to gauge its size in the absence of a reference. It is also unknown whether this flight was conducted from the ground, to validate the boosted sequence and booster/missile separation, or from an aircraft—RAFALE or otherwise.
ONERA had previously released images of wind tunnel tests of hypersonic missile models, some of whose rear sections might resemble that of THEMIS, but not the front section. This is even though the ASN4G itself may differ significantly from THEMIS, which may have been designed to meet different constraints than those of the future operational missile.
While the photo released on June 11 lifts a corner of the veil on the future ASN4G missile, the mystery surrounding it remains almost complete. It will likely take several more years before photos of the operational vector become available.
In the meantime, the CEA is also working on the future nuclear warhead that will equip it, the TNA4G, which will replace the current TNA. The great work of French nuclear deterrence continues inexorably, ensuring its long-term credibility, both in the eyes of national political and military authorities and those of our adversaries. /END
