There are reports today that the U.S. is potentially preparing to transfer AGM-158 Joint Air-To-Surface Standoff Missiles (JASSMs) to Ukraine as part of an upcoming aid package that will be executed in the coming weeks. While the JASSM is more advanced than any standoff weapon in Ukraine’s inventory and it would provide enhanced capabilities, its biggest benefit is that the U.S. government could supply a steady flow of the weapons, greatly expanding the number of high-priority target sets Ukraine can strike deep behind enemy lines.
The reports that JASSMs could be on the way to Ukraine would fit with a claim from a top-ranking officer in that country from months ago that donated F-16 Vipers would feature an advanced standoff missile with a range of between 300 and 500 kilometers (186 to 310 miles) as part of their weapons menu. It also would provide a mission for Ukraine’s fledgling Viper fleet beyond air defense, without taking on greater risk. Ukraine has already lost one of half a dozen F-16s delivered, as well as a precious Viper-trained pilot, although the circumstances of just how this occurred remain murky.
Right now, the Ukrainian Air Force employs the nearly identical Storm Shadow and SCALP-EG cruise missile types, donated by the United Kingdom and France, respectively, as their primary means of air-launched standoff strike. Both types are fired by Ukrainian Su-24 Fencers. Aside from U.S.-donated ATACMS ballistic missiles and indigenously-developed Neptune cruise missiles, these weapons represent the high-end of Ukraine’s long-range precision attack capabilities.
While Storm Shadow and SCALP-EG have similar basic performance to JASSM, the U.S.-made cruise missile is more survivable, featuring a high degree of low-observability (stealth) that reduces its signature to the point that it can wind its way through very advanced and dense air defense networks. This is done with the help of very high-fidelity and current electronic and other forms of intelligence and programmed into a mission planning interface that helps come up with the best route for the missile to survive its trip to its target. For terminal guidance, like SCALP-EG and Storm Shadow, imaging infrared is used together with scene/image matching technology to attack the right target even in a dense electronic warfare environment. The seeker system is thought to be very advanced and capable of pinpointing exact parts of structures to impact as programmed, even under varying atmospheric conditions. The first iteration of JASSM has a range of around 330 miles (although some sources have put it at around 230) and packs a 1,000-pound penetrator warhead capable of taking out hardened structures.
So, overall, Ukraine would get a more advanced and survivable missile for penetrating deeply into Russia’s air defense overlay that populates eastern Ukraine and Crimea. In the past, at least some Storm Shadow/SCALP-EG missions were assisted by ADM-160 Miniature Air-Launched Decoys (MALD). The ADM-160 is a mini-cruise missile-like decoy that exists to distract and confuse enemy air defense. JASSM’s stealth may allow it to hit the same targets as its French and British counterparts without the help of MALDs, or it will be even more effective with their assistance.
But the capabilities JASSM could provide really aren’t its biggest draw, it’s the fact that the U.S. has been working to stockpile thousands of these missiles and is building more advanced versions as fast as it can. Pentagon budget documents and Selected Acquisition Reports for the JASSM program show just over 2,000 AGM-158As were acquired before production of those missiles ended in 2021. The current “inventory objective” for total JASSM purchases, past and future, including the aforementioned A versions, as well as current and future subvariants of the JASSM-ER, is over 12,000.
AGM-158As first entered service in the early 2000s and B models began to follow in the mid-2010s. Some of the original missiles are aging and are likely approaching the end of their service lives or are in need of major overhauls to keep them fresh. So, the U.S. military could provide a steady stream of these weapons to Ukraine, at least the oldest and least advanced types. In comparison, Storm Shadow and SCALP-EG were not built in anywhere near the same quantities. While the United Kingdom and France have been generous with these weapons, the supply of them is limited and is likely already becoming a major concern. The United Kingdom is said to have hundreds not thousands of these missiles in total before they started flowing to Ukraine, for instance. JASSM could step in and stabilize the situation. This is similar to what the AIM-120 AMRAAM and NASAMS air defense systems provided, which you can read all about here.
For Russia, JASSM would mean that Ukraine has an advanced air-launched standoff weapon that is not heavily supply limited and can penetrate its best defenses. This would be a big problem for Russia, especially when it comes to key targets in Crimea, but also major staging areas, storage sites, command bunkers, training centers, and more, deep behind the front lines in Ukraine. They could even be used to hit more time sensitive targets under certain circumstances. As of now, the U.S. government has not allowed Ukraine to use advanced standoff weapons on targets in Russia and even less advanced ones have only been cleared for use when returning fire over the border. If this were to change, JASSM would become a massive problem for Moscow’s overstretched air defenses and no long-range drone can hit with anywhere near as destructive power.
One big concern with using JASSM in the Ukraine-Russian conflict is the technological sensitivities of the missile. While even its 20-year-old electronics and sensor technologies are still considered sensitive, its airframe, specifically its low-observable design features, and the material science that comes with it, would prompt the most concern.
U.S. JASSMs would be used in great numbers during a conflict with China as an absolutely critical standoff strike staple. So compromising their capabilities, in particular how to spot them or confuse their targeting seekers, could be a huge problem. Still, we don’t know what exact technical changes have been made to this family of missiles as it has evolved and whether providing the oldest ones to Ukraine would represent an extreme risk of being compromised as later production models and new variants. We also don’t know what China, Russia, and other adversaries already know about these weapons. If much of this has already leaked, the risk would be less.
JASSMs have been used before in combat and some bits of wreckage have possibly been exploited by foreign intelligence services. Still, these use cases have been very limited and in areas that the U.S. military can reach if it has to (Syria) in order to destroy a somewhat intact weapon, if it can be located. In Ukraine, Russia has recovered multiple Storm Shadow and SCALP-EG missiles in various states, some almost entirely intact, by Russian forces and sent back home for exploitation. Could the U.S. stomach this same outcome, as it is very likely to happen if JASSM gets put to use en-masse in the conflict?
We detail the security issue with JASSM in our previous feature on the weapons Ukraine could get for its F-16s. Things have changed since that was written, with ever more advanced weaponry being handed over to Ukraine, but the JASSM issue remains the same. It also can be argued that the U.S. will need every single one of these weapons (and ideally many more) in a major fight with China in the Pacific and that handing them over to Ukraine erodes the U.S. military’s ability to confront its top pacing threat.
As we noted in our feature, another option would be the AGM-84H/K Standoff Land Attack Missile-Expanded Response (SLAM-ER), which has been integrated, at least to some degree, onto the F-16 by Turkey. This weapon serves primarily with the U.S. Navy, as well as South Korea, and while it is not as advanced, hard-hitting, and long-reaching as the JASSM, it has some capabilities it does not, including man-in-the-loop targeting, that could be beneficial without JASSM’s technological risk.
We will have to wait and see if indeed this supposed deal to send JASSM to Ukraine actually comes to pass, but Ukraine’s F-16s could really use a standoff land-attack weapon in order to take a bigger role in the war effort so early on in their service – and just how many Storm Shadows and SCALP-EGs are left to donate is an increasingly concerning question.
Contact the author: Tyler@twz.com