The Pretis weapons factory sits in a narrow valley on the northern edge of Sarajevo, pressed against the steep, forested slopes that rise behind the Bosnian capital. Inside, cold war-era machines hammer at glowing steel heated to more than 1,000C.

Factories such as Pretis once produced hundreds of thousands of artillery shells each year for a European land war that never arrived. After the 1990s, many of the Bosnian production lines fell silent. Skilled explosives workers retired, and state-owned plants only survived by exporting modest quantities of ammunition to faraway conflicts.

Then, in the spring of 2024, a newly formed American company began buying up shares in Pretis and in another Bosnian arms factory, Binas. The company — Sitko Acquisition LLC — had no website, no public staff and no footprint beyond a US post-office box. Through a series of discreet trades on the Sarajevo stock exchange, Sitko became the largest private shareholder in both factories, second only to the Bosnian government.