I was recently looking through the topic wording and technology regarding missile defense peaked my interest. I was told by another member of the community that ballistic missile defense technology was not categorized as "arms."
In my brief reading through topic literature, I cannot find anything that speaks in a particular direction. It appears to me that most BMD systems use surface to air missiles, which I would think fall under category four on the USML. However, I cannot find any explicit reference to these operating systems being classified as arms under US code.
The controlling document, at least as explained to me, the AECA, was written well before the explosion of missile defense technologies during the 80s and afterward. I was wondering if you could point me toward any definitions of what constitutes arms sales or sales of arms that definitively create a distinction that allows missile defense to either be considered or not considered a sale of arms.
Thanks for your query. Alas, you've been misinformed, at least to some extent. Ballistic missile defense systems certainly are considered as arms and you'll see many sales falling under the foreign military sales (FMS) and direct commercial sales (DCS) programs. To date, the largest single FMS notification under the Trump administration has been for Terminal High Altitude Area Defense (THAAD) equipment, support, and services to Saudi Arabia. See the Forum's resource page and google spreadsheet for many other missile defense sales.
You can also find some more discussion of specific missile defense sales from the United States and more globally in this recent publications:
William Hartung and Christina Arabia, "Trends in Major U.S. Arms Sales in 2018: The Trump Record - Rhetoric Versus Reality," Center for International Policy, April 2019.
Aude Fleurant +, "Trends in International Arms Transfers, 2018," SIPRI, March 2019. (see box 1)