Since Russia's full-scale invasion of Ukraine, NATO arms and ammunition factories have struggled to ramp up output, while many European countries have depleted their stockpiles to meet the frontline needs of an ally under attack.
The escalation of the US trade war, including retaliatory tariffs and export bans, could jeopardize supply chains critical to Ukraine's defense.
The wide-ranging tariffs placed by the administration of US President Donald Trump on a slew of countries and industries could have far-reaching consequences for Ukraine's war effort. From advanced weapons that rely on Chinese-sourced rare-earth minerals to basic munitions, fewer rounds could reach the front lines -- constraining Ukraine's military operations at a crucial juncture.
Here's a look at how the components of even a simple bullet are affected.
The impact of tariffs would not only increase pressure on defense budgets -- it could reshape defense industry dynamics worldwide.
Let's break this down with a small-scale example.
Bosnia's Dual-Track Defense Industry
Bosnia and Herzegovina sits at a geopolitical crossroads between NATO aspirations and lingering Russian influence. It has the industrial know-how to produce both NATO-standard and Soviet-caliber arms and ammunition, serving a diverse clientele across the Middle East, Africa, and beyond.
While Bosnia is not yet a NATO member, it is a partner country and increasingly an indirect contributor to Ukraine's war effort.
The United States is a top buyer of Bosnian-made ammunition. Although Bosnia does not officially export arms to Ukraine, deliveries are routed through intermediaries.
Records show that significant US investments have been made to modernize Bosnia's arms production facilities, particularly for light weapons and ammunition.
Defense firms like Regulus Global view the country as an affordable manufacturing base offering relatively low-cost skilled labor and a legacy of Yugoslav-era defense infrastructure.
Bosnian military analyst Antonio Prlenda notes that just a decade ago, few would have expected the United States to engage Bosnia's defense industry so directly, given the calibers and equipment standards.
US investors, he says, have played a crucial role in reviving dormant factories, largely with Ukraine as the primary end user.
"After the Russian aggression to Ukraine, there was a huge need for artillery equipment, and the Bosnian defense industry is always famous for high-quality artillery pieces, artillery munitions, explosives, and fuses. And suddenly the huge rise in the need for that type of equipment became realistic."
Bosnia has been modernizing its defense sector with the help of the US government and American firms for decades. But the newly imposed tariffs could complicate joint ventures, procurement contracts, and export flows, potentially pushing Bosnia to pursue defense partnerships with non-US allies.
Tariffs could also increase the cost of Bosnian defense products, making them less competitive on price-sensitive global markets. This may trigger a decline in demand from US buyers and NATO partners, creating space for other regional actors.
Politically, tariffs could be leveraged to decouple Bosnia's defense sector from NATO priorities, redirecting its focus toward clients in the Middle East, Africa, or Asia.
Given Bosnia's growing role in supplying ammunition and small arms -- particularly to countries involved in the Ukraine conflict -- this would be a major setback for a defense industry on the track for former glory.
The Bosnian defense industry is shifting toward NATO-compatible calibers and aligning itself with modern battlefield trends such as drones and unmanned systems in order to remain competitive, Prlenda explains.
Yet serious challenges remain: A deteriorating industrial base, limited research and development funding, and a lack of institutional support are holding back domestic expertise and hindering international expansion.
Because Bosnia has a complex political situation, Prlenda says companies involved in the defense industry "cannot rely so much on diplomatic support from the government, and that makes things much harder for them."
Impact Of US Tariffs On Ukraine
Introducing tariffs into a complex, multinational defense supply chain reliant on imports of metals, optics, electronics, and propellants risks causing delays and cost overruns, not just in Bosnia but globally.
And Bosnia is just one small node in a vast network of suppliers supporting Ukraine's fight for survival.
Tariffs targeting this complex and sensitive supply and export system could have far-reaching and unintended consequences.
US defense contractors themselves may face rising production costs. The reliance on global suppliers means tariffs could lead to material bottlenecks, manufacturing slowdowns, and disrupted delivery timelines.
This could undermine US leadership in the global defense market and incentivize countries to reduce their dependence on American systems. The result may be a strategic shift toward "friendshoring" -- sourcing from trusted geopolitical allies to ensure continuity and affordability.
"My understanding is that for American equipment, it will not be a big impact, but for the components that come from other parts to the United States that would have definitely raised the price, and it will make trouble for some purchase of the equipment that will be sent to Ukraine," said Prlenda.
"But for the things that go through Europe or if you deal with some American companies that are European registered, that would be easier for them," he added.
Tariffs could significantly affect efforts to arm and support Ukraine by raising costs or reducing the volume of aid that can be delivered per dollar spent.
If US deliveries are delayed or reduced, European countries may need to bridge the gap, which could potentially trigger new tensions over cost-sharing within NATO.
As a result, Ukraine and its supporters may start to view the United States as a less dependable partner. While overall aid is not at immediate risk of collapse, Russia could exploit emerging rifts among Western allies.
