  In this briefing report, we introduce a new concept (war algorithms) that
elevates algorithmically-derived choices and decisions to a, and perhaps the,
central concern regarding technical autonomy in war. We thereby aim to shed
light on and recast the discussion regarding autonomous weapon systems. We
define war algorithm as any algorithm that is expressed in computer code, that
is effectuated through a constructed system, and that is capable of operating
in relation to armed conflict. In introducing this concept, our foundational
technological concern is the capability of a constructed system, without
further human intervention, to help make and effectuate a decision or choice of
a war algorithm. Distilled, the two core ingredients are an algorithm expressed
in computer code and a suitably capable constructed system. Through that lens,
we link international law and related accountability architectures to relevant
technologies. We sketch a three-part (non-exhaustive) approach that highlights
traditional and unconventional accountability avenues. We focus largely on
international law because it is the only normative regime that purports, in key
respects but with important caveats, to be both universal and uniform. By not
limiting our inquiry only to weapon systems, we take an expansive view, showing
how the broad concept of war algorithms might be susceptible to regulation, and
how those algorithms might already fit within the existing regulatory system
established by international law.
