In this report, the CSIS Harold Brown Chair in Defense Policy Studies analyzes the types of capabilities necessary across the range of military operations, and compares that with the characteristics of amphibious ships, as well as those in the Combat Logistics Fleet, Maritime Prepositioning Force, and others. Resulting shortfalls in key capability areas suggest some degree of risk. The study then describes how amenable those risks may be to mitigation and some of the associated implications. This report provides a framework for policymakers to understand those areas in which alternative platforms might be most useful, where risks associated with their employment are most significant, and how readily broadening platforms beyond the uses for which they were designed might be accomplished.