Approved for public release, distribution is unlimited / Many potential adversaries seek, or already have theater ballistic missiles capable of threatening targets of interest to the United States. The U.S. Missile Defense Agency and armed forces are developing and fielding missile interceptors carried by many different platforms, including ships, aircraft, and ground units. Given some exigent threat, the U.S. must decide where to position defensive platforms and how they should engage potential belligerent missile attacks. To plan such defenses, the Navy uses its Area Air Defense Commander (AADC) system afloat and ashore, the Air Force has its Theater Battle Management Core Systems (TBMCS) used in air operations centers, and the Missile Defense Agency uses the Commander's Analysis and Planning Simulation (CAPS). AADC uses a server farm to exhaustively enumerate potential enemy launch points, missiles, threatened targets, and interceptor platform positions. TBMCS automates a heuristic cookie-cutter overlay of potential launch fans by defensive interceptor envelopes. Given a complete missile attack plan and a responding defense, CAPS assesses the engagement geometry and resulting coverage against manually prepared attack scenarios and defense designs. We express the enemy courses of action as a mathematical optimization to maximize expected damage, and then show how to optimize our defensive interceptor pre-positioning to minimize the maximum achievable expected damage. We can evaluate exchanges where each of our defending platform locations and interceptor commitments are hidden from, or known in advance by the attacker. Using a laptop computer we can produce a provably optimal defensive plan in minutes. / Lieutenant, United States Navy