The Navy's latest 30-year shipbuilding plan has a force of 33 amphibious warfare ships as its objective. The primary purpose of those ships in wartime is to carry Marine Corps units overseas and to support and sustain them as they deploy ashore. In peacetime, amphibious ships perform various missions, such as engaging in routine patrols overseas, reassuring allies, responding to crises, and providing humanitarian relief. This book provides an overview of the size, missions, and use of the Navy's amphibious warfare ships and related expeditionary forces under the Navy's "2012 shipbuilding plan".