Replacing the military equipment transferred to Ukraine by the United States’ NATO allies could lead to roughly $21.7 billion in foreign military sales or direct commercial sales for American industry, according to research by the Foundation for Defense of Democracies’ Center on Military and Political Power.

At the same time, backfilling the weapons these allies have sent to Ukraine with U.S. equipment could improve their capabilities and build a more effective military deterrent while lowering the Pentagon’s cost to procure these weapons. It would also enhance the quality of the weapons U.S. warfighters wield and strengthen U.S. defense industrial base capacity.

In addition to the $26.7 billion worth of security assistance the United States has committed (as of Jan. 20) to Ukraine since Russia’s Feb. 24 invasion, other NATO members have contributed billions of dollars’ worth of equipment. It is difficult to calculate precisely the cumulative value because many countries, unlike the United States, do not publish detailed lists.

CMPP relied on open-source information from the military analysis site Oryx to establish a baseline regarding the types and quantities of arms non-U.S. NATO countries have committed to Ukraine. It then identified an analogous U.S. system and used data from Defense Security Cooperation Agency announcements of FMS sales to estimate the unit price of the respective American system. The center then added the cost of all replacement systems the U.S. could and would likely provide, which totals roughly $21.7 billion as of Dec. 5.

Admittedly, such analysis is somewhat imprecise, given the uncertainty in forecasting future decisions by allied governments. The research project, therefore, required several assumptions, which certainly can be debated.

Some countries may not replace equipment sent to Ukraine at a 1:1 ratio or may seek to acquire different American equipment than predicted. Moreover, some governments will buy equipment from non-U.S. manufacturers instead.

At the same time, the actual amount of equipment provided to Ukraine (and likely needing replacement) is almost certainly understated in this research due to some equipment being provided in unknown quantities or in secret. Additionally, many NATO allies are increasing their defense budgets significantly.

NATO countries (not including the United States) have cumulatively increased their real defense spending each year since 2015, and those levels of defense spending are likely to increase further following Russia’s latest invasion. Poland, for example, is raising its defense spending from 2.2% of its gross domestic product to 3%, which will help Warsaw purchase more military equipment.

Replacing the (often legacy) equipment NATO members have donated to Ukraine with modern American systems will improve the capabilities of individual NATO members and the alliance’s combined ability to deter aggression. For example, replacing Soviet legacy multiple launch rocket systems such as the BM-21 with High Mobility Artillery Rocket Systems, which have proven very effective against the Russian military, would allow NATO members to strike adversaries with greater precision and from greater range. Replacing Soviet-era T-72 tanks sent to Ukraine with M-1 Abrams tanks would yield similar benefits.

In addition, an alliance in which individual member countries employ more common equipment is one that can train and operate together more effectively and use more efficient logistics and sustainment systems.

Increasing production to backfill NATO members will also bring benefits for the Pentagon, U.S. service members and American taxpayers. Foreign military purchases of American equipment increase the quantities produced, which “may help lower unit costs by consolidating purchases for FMS customers with those of DoD,” according to the DSCA. That can help stretch the U.S. defense budget.

Increased and predictable multiyear demand for arms can incentivize the U.S. defense industry to invest additional money into research and development at the company’s own expense. Higher rates of investment in R&D can lead to more advanced weapons, helping ensure U.S. warfighters are wielding the best capabilities possible wherever they deploy, including in the Indo-Pacific region and the Middle East.

Increased demand for American equipment and munitions will also incentivize the U.S. defense industrial base to create much-needed additional production capacity. Current U.S. industrial base production capacity cannot adequately support the Pentagon’s most significant military modernization effort in four decades and arm Ukraine to defeat Putin’s invasion while ensuring Taiwan has the means to deter an invasion from Beijing.

To be sure, investments in additional production capacity often don’t yield fruit for some time. Moreover, any additional production capacity created in the short term should be used first to equip American forces and beleaguered democracies such as Israel, Taiwan and Ukraine confronting grave current or prospective threats. With the exception of allies on NATO’s eastern flank, shipments of American arms to Europe should only come after those urgent requirements are addressed.

Regardless, decisions now to eventually backfill NATO allies with American arms to replace those sent to Ukraine will help strengthen U.S. and transatlantic security and enable the United States to once again become the arsenal of democracy. That will have benefits far beyond Europe.

Ryan Brobst is a research analyst at the Foundation for Defense of Democracies, where Bradley Bowman is the senior director of the Center on Military and Political Power.

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