The Interwar Period International Trade in Arms: A New Dataset

International weapons transfers send military capabilities, make arms production economically feasible, and construct security relations. They influence buyers’ and sellers’ foreign policies, domestic politics, and military spending behavior. However, data availability has limited their study to the bipolar Cold War and unipolar post-Cold War periods. We thus introduce the Interwar Period International Trade in Arms (IPITA) data, covering dyadic transfers of small arms, light weapons, ammunition, explosives, and major conventional weapons in the years 1920–1939. The IPITA data will offer new avenues to study the drivers, dynamics, and consequences of arms transfers, both in past and future multipolar systems.