The United States has provided Ukraine with the most military support since the beginning of the Russian aggression.[1] To date, it has pledged $37.3 billion in military aid and has transferred equipment and weapons, including 10,000 Javelin anti-tank systems and 4,000 TOW missiles, 1,600 Stinger anti-aircraft systems, and an unspecified number of HARM anti-radar missiles (for use on F-15, F-16, F/A-18, and F-35 aircraft, but adapted to Ukrainian MiG-29 and Su-27 aircraft). Ukraine also has received 160 155mm howitzers (including 18 M109 Paladin self-propelled howitzers and M198 and M777 towed howitzers), 72 105mm M119 towed howitzers, as well as 2 million rounds of 155mm artillery ammunition and hundreds of thousands of rounds of other ammunition types, including Excalibur precision munitions for artillery systems. American aid also includes HIMARS rocket artillery systems, NASAMS air-defence systems, armoured vehicles (M113, M1117, MRAP) and combat vehicles (Bradley, Stryker),[2] unmanned aerial vehicles (Switchblade, Phoenix Ghost, Puma, CyberLux K8, Altius- 600, Jump-20), anti-drone systems (including Avenger), radar systems, communications, and other equipment.

Gaps resulting from such extensive support are not filled on an ongoing basis, due to the slow bureaucratic process and the unpreparedness of the American defence sector to elevate to “war production” levels. Major defence industry concerns such as BAE Systems (a subsidiary of the British firm), Boeing, General Dynamics, Lockheed Martin, Northrop Grumman, and Raytheon cut production capacities after the end of the Cold War, so rebuilding them will be a political, financial, and organisational challenge.

Military Support for Ukraine in the Political Debate

Since the Biden administration and most Democrats make support for Ukraine a foreign policy priority, some opposition Republican Party politicians automatically question the aid. The most visible group of them, but also the least numerous in Congress, are generally anti-Ukrainian politicians who oppose any further U.S. involvement in helping Ukraine. They point to domestic problems that, in their opinion, should be higher priorities for the administration. Among the Republicans there are also those who believe that helping Ukraine is tantamount to ignoring the threat from China and therefore constitutes a waste of valuable resources. However, Republicans in Congress with a decisive role in shaping foreign policy favour continued support for Ukraine, sometimes even criticising the Biden administration for being too restrained. Among them are the Chairman of the House Foreign Affairs Committee Michael McCaul, who has been urging the Biden administration to transfer long-range ATACMS missiles to Ukraine, and the Ranking Member of the Senate Foreign Affairs Committee Jim Risch, who has been supporting the transfer of F-16s to Ukraine since the first weeks of the Russian invasion. An indirect threat to aid to Ukraine is posed by proposed cuts in federal spending aimed at reducing the budget deficit, as generally advocated by the Republicans. Although the course of the internal debate indicates that the Republicans will not seek to reduce military spending overall, it is not certain whether this will also apply to military support for Ukraine (they may instead limit economic and humanitarian aid).

Support for Ukraine is also a potential topic of debate in the Republican primaries before the presidential election in 2024. Donald Trump, who is seeking re-election, and Florida Governor Ron DeSantis, Trump’s main challenger, are both opposed to further support. They have stated that U.S. involvement is fomenting war and wasting resources that should be used for other purposes, including sealing the border with Mexico and fighting drugs on domestic soil. Nikki Haley, the former governor of South Carolina and U.S. ambassador to the UN under Trump, is also running for president and in her campaign has emphasised that maintaining aid to Ukraine is necessary (pointing to arms transfers, but questioning economic aid), and that Russia’s defeat will be a clear signal to other U.S. opponents. She sees the Russian invasion in a broader context and is calling for a return to a more traditional Republican concept of foreign policy. Another candidate, former Arkansas Governor Asa Hutchinson, takes a similar approach.

U.S. Military Stockpile Gaps

The military support of Ukraine has cut into the resources of the U.S. armed forces.[3] The transfer of more than 10,000 Javelin systems to Ukraine reduced stockpiles of that weapons system by about 40%, according to public information. The current capacity of industry to resupply them is about 2,000 units per year. At this rate, the replenishing of storage facilities will take about five years, while also considering additional transfers of these systems to Ukraine. The U.S. supplies to Ukraine of older-generation TOW anti-tank missiles may indicate limitations to supplying further Javelin systems. The U.S. also transferred to Ukraine about 1,600 Stinger systems, or about a third of the whole armed forces stockpile. The current production rate allows for about 500 units per year, which means that just replenishing stocks to the previous level would take more than three years.

Rebuilding the stock of howitzers, especially the M777 type, may also be a problem. They are the basic type of towed howitzer used by the U.S. armed forces. Production of this platform has ended (they were most recently produced for export to India), but the manufacturer, BAE Systems, is in talks with the U.S. and other countries about resuming production. The company estimates that restoring the production lines alone may take up to three years, due mainly to the lack of contracts for the necessary raw materials and components. For this action to be profitable for the concern, orders for new M777 howitzers would have to total at least 150 units. In order to provide Ukraine with more M777 howitzers, the Department of Defense would have to obtain them from operational units, which is currently considered an unacceptable risk. The M119 and M198 howitzers also are no longer produced, but the U.S. most likely has sufficient stocks of them—about 600 M198 howitzers (no longer used by active units) and about 400 M119 howitzers (most of them were converted to 155mm).[4] Future transfers of howitzers will depend on the ability to transfer sufficient amounts of ammunition, as well as on the possible readiness of the U.S. authorities to change its artillery capabilities and replace traditional artillery with, for example, HIMARS rocket systems.

The transfer of two million 155mm artillery rounds has seriously depleted U.S. stocks and the capacity to replenish them is limited. This is due not only to the limited production capacity of the concerns but also to problems on the global market in obtaining the necessary chemical components and explosives to produce ammunition. The U.S. has transferred most of the stockpiled Excalibur precision rounds (about 7,000 units), but after doubling the production capacity, it still will only be able to replenish its stocks in more than five years.[5] As a result, the transfer of M119 howitzers and 105mm ammunition, which are no longer widely used by the U.S. armed forces, is more likely.

Speeding up Defence Industry Output

Production difficulties and delays are not exclusive to armaments for Ukraine but are a common phenomenon in the delivery of contracted armaments to foreign partners through the Foreign Military Sales (FMS) procedure. On average, over the last decade, delays in contract performance ranged from two to five years.[6] The U.S. authorities blame the delays on defence companies, which in turn explain them by supply-chain disruptions and labour shortages caused by the COVID-19 pandemic. They also result from the numerous administrative procedures conducted by the departments of State and Defense as part of the FMS proceedings and the related set of regulations on export controls of military technology (ITAR). In the context of support for Ukraine, funds allocated by the government for military assistance are processed according to the Presidential Drawdown Authority (PDA) and the Ukraine Security Assistance Initiative (USAI) long-term support programme.

To better arm allies and increase the credibility of the conventional deterrence of China and Russia, in August 2022 the Pentagon created a working team tasked with improving the administrative side of the arms-sale process in the FMS procedure. It is also intended to increase the competitiveness of the American defence sector in the competition with China and to rebuild the capabilities of allies who have transferred significant amounts of weapons to Ukraine. In addition, the Biden administration implemented provisions of the Defense Production Act (DPA), which is used to prioritise selected contracts carried out by the private sector, including to accelerate the acquisition of chemicals and explosives for the production of ammunition and missiles, as well as mechanical and electronic components,[7] and to increase the production of printed circuit boards for integrated circuits used by, among others, the defence companies.[8]

The provisions contained in the federal budget for the 2023 fiscal year enable the U.S. authorities to obtain contracts (including long-term contracts) for the production of ammunition and armaments that are key elements of Ukraine’s support—155mm artillery and precision ammunition, Javelin and Stinger systems, HIMARS launchers and missiles, and also AMRAAM missiles, which Ukraine may soon receive, PAC-3 missiles used in Patriot systems, and ATACMS missiles, which may become an element of military assistance in the future. Including these provisions in the budget is not tantamount to ordering individual types of armaments. In the short and medium term, as long as the orders are not placed and implemented, the quantitative gaps in some of the capabilities may deepen along with the continuation of military assistance to Ukraine.

Stimulating Industry

During the 15 months of the Russian full-scale aggression against Ukraine, the growing demand for selected systems and the increasing interest of many countries in acquiring them has mobilised some defence companies to increase their production capacity. For example, the manufacturer of the Javelin system, a consortium of Raytheon and Lockheed Martin, plans to nearly double capacity to 4,000 systems per year from about 2,000, and the U.S. authorities are conducting talks regarding the production of these missiles in Poland.[9] For the Stinger systems, the U.S. expects production to reach around 700 per year by 2025, which will allow stocks to be replenished in just over two years. Prior to Russia’s invasion of Ukraine in 2022, production of these systems was maintained by Raytheon to fill orders from Taiwan. In 2022, further orders were placed by the U.S. (to fill the gaps) and Finland.[10] Increasing the production capacity of both the Javelin and Stinger systems will allow for faster replenishment of stocks and equipping allies and partners with them, including Taiwan. In addition, the Pentagon has accelerated the search for a system that will ultimately replace Stingers in the U.S. armed forces.

The industry has responded to calls for more artillery ammunition. The current rate of production of 155mm ammunition has increased from 14-20,000 units per month (according to the Pentagon’s estimates, Ukraine uses 4-5,000 units of artillery ammunition of various calibres daily), and the target production is to be 70,000 units per month in 2025. In turn, the production rate of Excalibur munitions has more than doubled from less than 100 to about 200 units per month. In addition, the U.S. authorities are allocating additional funds to speed up the production of HIMARS launchers (also in order to fill the gap from the donated M777 howitzers) and GMLRS rockets (production is to increase by about a third), for which the current production rate is estimated at 5,000 units per year. Accelerating the production of the HIMARS launcher is also important from the perspective of allies interested in acquiring this system, including Poland, which has obtained consent to purchase them.[11]

Since the decisions of the defence companies are influenced by calculations of financial risk, one of the elements necessary for an increase in production capacity is the conclusion of contracts for the supply of specific types of armaments, which are a clear signal of the need for and commitment to financing. The deals with the greatest stability in the U.S. system are multi-year contracts, which are often used for heavy armaments, but rarely for rockets and ammunition.[12] Including the possibility of such contracts in the budget for fiscal year 2023 is therefore a positive signal to the industry. Difficulties in increasing industrial production also result from disruptions in supply chains, as well as dependence on the supply of critical components or raw materials from one supplier. The U.S. authorities strive to reduce such monopolistic dependencies, including on foreign entities from countries perceived as U.S. rivals, such as China. However, this kind of systemic change will require many years of political consistency in investing in the U.S. economy, as well as entering into technological partnerships with allied governments and companies.

Prospects for Further Support for Ukraine

Although maintaining support for Ukraine at the current level will be a challenge, its potential can be strengthened by the transfer of more modern and advanced types of weapons. In January this year, the United States decided to provide Ukraine with 31 Abrams tanks[13] as part of a broader coalition of Western countries that are also donating Leopard 2 and Challenger tanks. The U.S. made this decision despite the extended delivery time of the tanks (early 2024 was given as a real date). To speed up this process, the administration decided to refurbish used units (M1A1), which will allow them to be delivered this fall, instead of ordering new tanks (M1A2) from the manufacturer (General Dynamics), which would arrive in 2024 at the earliest.

The Biden administration is still undecided whether to provide Ukraine with ATACMS missiles, which have a range of more than 300 km, because of concerns about their use to attack Russian territory (which the U.S. administration considers an unacceptable escalation). In addition, the U.S. authorities point to insufficient quantities of these missiles in their own stockpiles to transfer them without compromising the capabilities of the U.S. armed forces in the short term. For this reason, even the provision of missiles with a similar range by other countries (including the Storm Shadow system supplied by the UK) may not persuade the U.S. to transfer the ATACMS. As an intermediate solution, the U.S. committed to provide Ukraine with precision GLSDB gliding bombs, which would allow it to hit more distant targets than the missiles fired from HIMARS launchers (the range is double that of the GMLRS, which can reach up to about 150 km). Even then, these bombs must be ordered from the manufacturer (Boeing), so it will take at least a few months to assemble and deliver them to Ukraine.

The U.S. also decided not to provide Ukraine with fighter jets, such as the F-16. The obstacles cited include the extensive pilot training time,[14] arguing that they want to focus on support that gives Ukraine an advantage in the short term. However, the argument of extended training time was weakened by the actual time it took to train Ukrainians on, among others, the Patriot missile defence systems. The Pentagon sped up the training time, ultimately to about 10 weeks, to get these systems to Ukraine faster. In turn, the transfer of Abrams tanks was also declared despite the argument of extended delivery time. In May, the U.S. declared that it would join a programme to train Ukrainian pilots on the F-16 together with other countries. According to the Pentagon’s estimates, it may last about four months. However, this does not mean handing over these fighters to Ukraine, although it brings the prospect of making such a declaration closer. The U.S. authorities still argue that they want to focus on short-term capabilities, while pilot training is focused on medium and long-term support. Previously, they also raised the argument of infrastructural limitations of the airports where the F-16s would be stationed and that these fighters have higher standards of inspection and service (compared to post-Soviet fighters). In addition, the U.S. is concerned with these specific fighters—like with the ATACMS missiles—that they will enable attacks deep into Russian territory, which Russia will consider an escalation carried out with the consent of the U.S. In addition, the Americans argue that the airspace over Ukraine is insufficiently secured by defence systems to ensure the effective operation of F-16 fighters. This argument is also used to block the transfer of MQ-9 Reaper unmanned aerial vehicles capable of carrying weapons, which Ukraine also requests.[15] However, the U.S. administration is striving to provide Ukraine with additional airspace capabilities that can be used by Ukrainian post-Soviet aircraft, including those received from other countries (e.g., Poland and Slovakia). Ukraine has received JDAM-ER precision bombs, most likely carried, like HARM missiles, by MiG-29 and Su-27 aircraft, and the U.S. plans to integrate AMRAAM guided missiles with them as well.[16]

Concerning artillery ammunition, there is a prospect of increasing transfers to Ukraine. The U.S. has millions of cluster-type artillery ammunition, including an MLRS variant for HIMARS. Although this type of ammunition is banned under a 2008 UN Convention, the U.S. is not a party to it (nor is Ukraine), and at the same time it is not widely used in combat operations by American troops—last used in Yemen in 2009, and earlier on a larger scale in 2003 during Operation Iraqi Freedom.

To maintain the current pace of support for Ukraine in the supply of ammunition and artillery shells, the U.S. decided to take ammunition from a stockpile located in Israel, meant for restocking in the event of a conflict in the Middle East. The decision was also made to use stockpiles in South Korea, Kuwait, and Germany.[17] Excluding Germany, which provides military aid to Ukraine, this decision posed a political challenge to the U.S. authorities. Although these are American armed forces stockpiles, their management (and thus the collection of weapons and ammunition) is carried out in consultation with the authorities of the countries where they are located. Israel, South Korea, and Kuwait have so far not decided to provide military support to Ukraine, fearing escalation with Russia, which is why there was uncertainty about their reaction to the plans of the Biden administration to use these stockpiles. In addition, the U.S. purchased from South Korea artillery ammunition, but without permission for re-export to Ukraine—only for the replenishment of American stockpiles. In turn, the U.S. bought 90 post-Soviet T-72 tanks from Czechia, which, after refurbishment (paid jointly by the U.S. and the Netherlands), were transferred to Ukraine. It also is buying back post-Soviet ammunition, including 122mm and 152mm artillery pieces, for example, from the countries of the former Warsaw Pact. The U.S. also provides non-repayable grants to countries that are involved in arming Ukraine through the Foreign Military Financing programme—it has transferred $1.8 billion since the beginning of the invasion to 15 countries in Central and Eastern Europe.

Potential Consequences for Allies

The rate of use of various types of equipment and ammunition during the war in Ukraine shows how serious a challenge it would be for the U.S. and its allies to engage in an armed conflict with Russia or China, and even more so with both at the same time. According to the strategic assumptions, the U.S. should be able to engage in a full-scale conflict with an adversary of comparable potential in one region, and at the same time effectively deter another adversary in another region or resolve the conflict on favourable terms through joint action with allies. When providing military support to Ukraine, the U.S. authorities assess whether it has a negative impact on their ability to defend strategic interests and fulfil allied obligations. However, since the current industrial potential, together with the procedural path, make it impossible to quickly replenish used equipment and ammunition, there are fears that the credibility of the American conventional deterrent may be weakened. Since the U.S. treats China as a long-term threat, allies in Europe must assume that in the event of Russian aggression against NATO, the U.S. will support the Alliance’s collective defence mission, but European countries will have to provide a significant part of the conventional capabilities. The credibility of NATO’s defence and deterrence strategy, which is adapted to the Russian threat, will therefore depend not only on the U.S. ability to fill capability gaps but also on the ability of its allies to fill similar gaps and develop their own capabilities.

The threat resulting from gaps in the resources of the U.S. armed forces is also emphasised in the American debate in the context of a possible conflict between China and Taiwan. Among the branches of the U.S. armed forces, the Army is the most burdened with the transfer of arms, followed by the Marine Corps. Due to the involvement of the U.S. in supporting Ukraine, the expectation (internal and international) has grown that the U.S. will be involved in the defence of Taiwan in the event of a threat to an extent at least equal to the level of support for Ukraine. This is due to President Biden’s repeated assurances about the U.S. readiness to defend Taiwan (although later clarified by the White House)[18] and the perception of possible Chinese aggression against Taiwan in the broader context of contesting the existing international order (similar to Russia’s invasion of Ukraine). The risk of possible shortages in the event of the need to support Taiwan is sometimes one of the arguments raised by the opponents of supporting Ukraine. Although Ukraine’s support does not directly affect Taiwan’s arming process, it puts additional pressure on the defence sector to deliver arms to allies and replenish American warehouses. The rate of consumption of ammunition and rockets during the fight with Russia has shown the need for industrial mobilisation in the event of direct U.S. involvement in a conflict. At the same time, the calculations regarding the U.S. military’s involvement in Taiwan’s defence may be affected by the lack of formal security guarantees towards the island (the U.S. is only obliged to support defence through arms sales) and concerns about the risk of escalation and direct conflict with China. As a result, more attention is being paid to the problem of arming Taiwan in peacetime. The reason for this is the belief that, unlike in the case of Ukraine, arms transfers to Taiwan will not be possible if China attacks, given the probability it will block all sea and air routes to the island.

Conclusions and Perspectives

While the support provided to Ukraine by the U.S. is depleting the stocks of American units, it allows for an indirect war with Russia, thus weakening the latter’s military potential. For this reason, it will be crucial to maintain military support for Ukraine and provide it with more types of weapons. Replenishing stocks and raising production to a level consistent with the rate of depletion will be a significant challenge that may weaken the political determination to continue the support for Ukraine, as well as raise questions about the overall military credibility of the U.S. The priority of the American authorities should be to increase the production of those types of weapons that are being transferred to Ukraine, as well as constituting other potential areas of military support. In this dimension, it will be crucial to persuade the defence industry (by placing long-term orders) that the requests are for the long term, both in replenishing the U.S. stockpiles as well as filling orders from allies and partners. To achieve this goal, the administration should take quick decisions to conclude long-term contracts, made possible by the 2023 budget. On the other hand, in the international dimension, a clear signal would be a constant increase in state spending as part of defence budgets, including for the purchase of armaments. Accelerating production (along with streamlining the American administrative procedure) may also result in increased interest from foreign partners, who may be persuaded by the prospect of faster delivery of armaments.

One of the goals of streamlining administrative procedures in the FMS process should be to facilitate the replenishment of stocks of allied countries, which also transfer significant amounts of equipment and ammunition to Ukraine. In this regard, it would be helpful for the U.S. to start talks with other countries about transferring part of their production capacities to their countries’ territories (as in the case of talks with Poland about the production of Javelin systems) or to invest in the development of industrial sectors of its allies and partners in Europe. These actions would ensure continuity of support for Ukraine, and in the longer term, also increase the responsibility for regional security by European states.

From the perspective of the mobilisation of the administrative apparatus, it seems crucial for the U.S. authorities to determine in which areas of the arms transferred to Ukraine it is possible to apply the provisions of the DPA in order to prioritise their production. Due to possible shortages of raw materials and components, it cannot be ruled out that the DPA may be applied to subcontractors that provide these materials, and not to defence concerns producing weapons. Therefore, even greater use of the DPA in the short term will not solve the problems of resource gaps and production delays.

Due to the limited production capacity and, as a consequence, further straining of the Pentagon’s stockpiles, as well as political barriers regarding the transfer of new types of weapons to Ukraine, in the coming months, the American military support packages will most likely be limited primarily to ammunition and missiles, as well as complementing the equipment already in Ukraine’s possession. The Biden administration may not be ready for the transfer of artillery cluster munitions, in part because of the threat to civilians posed by unexploded ordnance.[19] This, in turn, reduces the likelihood of handing over more howitzers and HIMARS launchers. A helpful measure is the EU countries’ decision to provide Ukraine with 1 million rounds of 155mm artillery ammunition in 2023 and to increase the production capacity of European industry.[20] As part of the Ukraine Defense Contact Group, the U.S. could seek to secure more ammunition for artillery from other countries, which then would provide the basis for the transfer of more howitzers.