Anti-access and area denial — best known by its shorthand A2/AD — has crossed the buzzword threshold. It's a quite impressive feat for such a distinctively non-user friendly and technical concept, which alludes to that family of military capabilities used to prevent or constrain the deployment of opposing forces into a given theater of operations and reduce their freedom of maneuver once in a theater. A2/AD's popularity may well be justified. For all its possible criticisms and shortcomings, the concept can help us better understand the unfolding global competition for military access and movement in an increasingly mature precision-strike context.
The A2/AD shorthand began to gain public traction among U.S. China-watchers less than two decades ago, proving rather handy in capturing Beijing's efforts to shut the U.S. military out of the Western Pacific area of operations. It soon became a popular concept in East Asia, too, as it turned out to be a recurring hook in conversations about the defense strategies of Japan, Australia, and other U.S. allies in the region.
A2/AD also found its way into strategic debates on the Middle East and Europe. Its ride in Europe has been particularly impressive, having become part of NATO jargon in a relatively short time span. This is hardly surprising. After all, Russian advances in A2/AD seem to challenge NATO's erstwhile assumption that Moscow could be deterred by a readiness-only approach that ensured allied troops would be in a position to move swiftly from North America and western Europe into the eastern European front. As former NATO Deputy Secretary General Alexander Vershbow put it, any allied aircraft, vessels or troops flowing from west to east would be highly vulnerable to Russian surface-to-air, anti-ship and land-attack missiles. Jānis Garisons, State Secretary of the Latvian Ministry of Defense, joked that in the Baltics, “even housewives were talking about the A2AD challenge in northeastern Europe.”