Delays in Key Weapon Deliveries to Ukraine

Author's Note: This article was originally published on August 29th, 2023.

Ukrainian requests for key weapons systems since the beginning of Russia’s invasion in February 2022 have met with varying success. Some systems were approved for export and delivered within days of an official request, others are awaiting delivery months after approval, and still others have yet to be greenlit at all. The following analysis seeks to explain this variation. Ultimately, a combination of escalation concerns, procurement complications, logistical considerations, apprehension regarding sensitive technologies, and political dynamics—among other factors—largely explain disparities in lag time between Ukrainian requests for key weapons systems, their approval, and their ultimate delivery. 

            Many Ukrainian weapons requests were denied or delayed due to escalation concerns vis-à-vis Russia. Generally speaking, longer-range, offensive systems carrying higher escalation risk took longer to approve. For instance, although President Zelensky first requested HIMARS in mid-April 2022, [1] the U.S. only approved their transfer on June 1^st, due to concerns that the system’s extended range could be used by Ukrainians to strike targets in Russia proper—a red line for Moscow. [2] In contrast, the U.S. had no such qualms with respect to short-range anti-armor weapons, and successfully delivered over 17,000 of them within the first six days of hostilities. [3] Moreover, despite being approved in on the first of the month, HIMARS only arrived in Ukraine near the end of June, the intervening time having been used to downgrade the system to prevent it from firing longer-range munitions. [4] A similar dynamic played out with the UK’s Storm Shadow missiles, which were finally provided in May 2023 after the UK imposed political limits on their use: in exchange for the missiles, Ukraine agreed not to use them against assets within the Russian Federation’s internationally recognized borders. [5] Likewise, approval to transfer Patriot missile defenses and F-16s has been a drawn-out process, in part due to concerns that these systems could be used to target Russian air assets flying over their own territory. Shorter range air defenses like MANPADS and NASAMS, as well as MiG-29s with limited engagement ranges relative to the F-16 were much more rapidly approved and transferred to Ukraine than their counterparts with longer reach. [6]

However, procurement and backfill challenges also played a significant role in the delays associated with transfers of advanced Western weapons systems. Despite having been a top priority request from the first days of conflict, [7, 8, 9] additional integrated air defenses were not delivered to Ukraine until April 2022. [10] Though Slovakia preliminarily approved the transfer of S-300 systems to its eastern neighbor in mid-March, [11, 12] deliveries were held up for several weeks due to the need to backfill Slovakian air defenses with U.S. and German Patriot systems. [13] Similarly, although third-party F-16 transfers were approved by the U.S. in May 2023 [14] and Norway, Denmark, and the Netherlands have pledged to supply Ukraine with a combined total of approximately 70 aircraft, they are only likely to do so after backfilling their squadrons with F-35s, most of which are expected to begin delivery later this year. [15, 16, 17] As a result, the first few F-16s are expected to arrive in Ukraine in late September 2023, with deliveries anticipated to continue incrementally through 2025. [18] This means it may be months before Ukraine fields the minimum quantity—one squadron [19]—of advanced fighters deemed necessary to defend its territory, and perhaps years before it operates the three or four squadrons required to dominate its own airspace. [20]

Procurement challenges likewise bedevil the future supply of Western air defenses. Although the U.S. has committed 12 NASAMS to Ukraine, only two have been provided so far, with the remainder intended to be delivered as they are procured through the end of 2025. [21, 22] The same is true for the Patriot system: only two have been delivered, [23] yet high-level Ukrainian officials insist that at least 10 to 12 Patriot-class systems are needed to cover the whole country. [24] Moreover, despite Raytheon’s recent announcement that it would accelerate production of Patriot systems, only 12 are anticipated to be procured per year at the new rate, meaning it will be quite some time before Kyiv receives the full complement of integrated air defenses it needs—assuming the U.S. approves future transfers. [25] Likewise, Ukraine requires far more MANPADS and portable anti-tank weapons than the Western defense industrial base can supply; at least 500 Stinger and 500 Javelin missiles are needed per day to satisfy Ukraine’s air defense needs. [26] Though Raytheon has restarted Stinger production [27] and Lockheed has nearly doubled its Javelin production rate, [28] these measures will yield results in years––not weeks––and will produce munitions in quantities that fall woefully short of the aforementioned figures.

Logistical issues also influenced delays. For instance, early offers by allied nations to transfer Soviet fighters to Ukraine were stymied by politico-logistical hurdles. In the firsts few weeks of the war, Poland offered to transfer its entire fleet of MiG-29s to Ukraine, using the U.S. as an intermediary. [29] However, the bid would have involved fighters departing from U.S. or NATO bases flying into airspace contested by the Russian Air force—a proposal that “rais[ed] serious concerns for the entire NATO alliance”, according to Pentagon Press Secretary John Kirby. [30] Though these concerns have since abated—Poland successfully transferred four MiG-29s in March 2023, and Slovakia soon followed by approving the transfer of 13 fighters and delivering four of them in quick succession [31]—logistical problems of another sort have also complicated the delivery of Western tanks and aircraft. Concern about Ukraine’s ability to meet the maintenance and logistical requirements of advanced Western platforms in the field contributed to American hesitancy to greenlight M1 Abrams and F-16 transfers. The M1 Abrams is infamously fuel-inefficient, uses jet fuel rather than diesel, and is difficult to maintain, requiring a complicated and costly logistical tail to operate. [32] Similarly, the F-16 requires months of training—not just for pilots but also for more numerous ground personnel—as well as the creation of a robust supply chain of replacement parts essential for ongoing flight operations. [33]

Though logistical concerns likely influenced delays in approving the transfer of advanced platforms, the desire to keep sensitive technologies out of Russian hands likely played a larger role in delays associated with the delivery of already-greenlit technologies. For instance, although the U.S. announced it would supply Ukraine with 31 Abrams tanks in January 2023, [34] none have been delivered so far. [35] The delay is primarily due to the need for ‘armor swapping’––the Abrams’ advanced depleted uranium armor must be stripped out and replaced with a tungsten variant, eliminating the risk of advanced armor technology falling into enemy hands. [36] As a result, however, the first deliveries of M1 Abrams are not expected until September—long after Ukraine’s counter-offensive began in June—with the initial batch numbering as low as 6 tanks. [37] Admittedly, the relationship runs the opposite direction as well; delays associated with removing sensitive technology reduced the chances that weapons systems would be approved for transfer. America’s Gray Eagle provides a case in point. Although the U.S. considered requests to transfer the drone to Ukraine—in fact, Congressional leaders pushed for its provision—the prospect of downgrading Gray Eagles to mitigate the risk of sensitive components falling into Russian hands seems to have proved sufficiently costly or time-consuming as to kill the proposal. [38]

Finally, political considerations played a pivotal role in delays associated with the approval of key Western technologies. Germany, for instance, refused to supply Leopard 2 tanks to Ukraine—or to approve third-party exports of the same [39]—without an American commitment to provide M1 Abrams. [40] Berlin’s foot-dragging is likely attributable to Germany’s political culture, which features a deep-seated hesitancy to lead the continent in military affairs in light of the nation’s history as Europe’s two-time aggressor. [41] In spite of Germany’s delays, at least 240 Leopard 1, Leopard 2, M1 Abrams, and Challenger 2 tanks have been pledged to Ukraine, with approximately one-third having been received [42] and deliveries expected to be completed by early 2024. [43] Though this falls short of the 300 tanks Ukraine needed for its 2023 summer offensive, the figure increases to over 575 tanks when including modernized Soviet models delivered to Ukraine from all partners. [44]

Ultimately, while no single factor readily explains the variation in lag time between Ukrainian requests for key weapons systems, their approval, and their delivery, examination of the aforesaid considerations yields several insights. Longer-range weapons systems have been more likely to be delayed, either due to fears of escalation or the need to modify such systems to reduce perceived risks. Similarly, weapons systems that contain sensitive technology, that fill key deterrent roles, or that are minimally stockpiled have been less likely to be approved for transfer and more likely to be delayed in delivery due to the need to mitigate the risk of enemy capture, to backfill the capability, and to maintain sufficient stores, respectively. Although some examples seem to buck the trend—like the U.S.’s rapid provision of thousands anti-tank weapons immediately following the invasion—ongoing transfers of a similar scale have failed to materialize due to procurement hurdles and dwindling inventories. These constraints notwithstanding, the United States and its allies appear committed to supplying Ukraine with sufficiently advanced weapons systems in sufficient numbers to keep them in the fight.