A2/AD

Anti-Access/Area Denial (A2/AD) describes a defensive strategy in which a nation deploys overlapping layers of missiles, radars, electronic warfare systems, and naval assets to deter or destroy an approaching force before it can operate effectively. The concept gained prominence in Western military planning during the 2010s as China and Russia invested heavily in long-range strike capabilities designed to keep U.S. carrier strike groups and expeditionary forces at bay.

A typical A2/AD network combines anti-ship ballistic missiles like China's DF-21D, integrated air defense systems such as the S-400, coastal defense cruise missiles, and submarine patrols. The goal is not necessarily to win a decisive battle but to raise the cost of entry so high that an adversary is deterred from attempting force projection into the defended zone.

Countering A2/AD has driven major investments in stealth aircraft, long-range precision strike, electronic warfare, and distributed force concepts. The U.S. military's development of weapons like the LRASM anti-ship missile, the B-21 Raider stealth bomber, and the concept of Agile Combat Employment all stem directly from the challenge of operating inside contested A2/AD environments.