Over the past 25 years, in an attempt to develop a speed-of- light hard-kill weapon system, the U.S. Navy has successfully reduced megawatt-class chemical laser and high power beam control technologies to engineering practice. This Navy program was established during the cold war era when defending naval battle group was the primary concern of the U.S. Navy. Since the collapse of the Soviet Union, however, an urgent and challenging issue facing the U.S. Navy is the self-defense against cruise missile in a littoral battlefield environment against threats originating from shore and/or scattered low- value platforms. This fundamental shift in the battlefield environment and engagement configuration profoundly affected the basic performance requirements placed on potential shipboard high energy laser weapon systems (HELWS). In a littoral maritime environment, thermal blooming limits atmospheric propagation of an HEL beam, and thus limits the weapon's effectiveness. This paper identifies and discusses the technical issues associated with HELWS requirements in this new environment. It also discuses the collateral capabilities that enhance and complement the performance of other weapon and sensor systems onboard ship. This paper concludes that the HELWS using a free electron laser (FEL) offers a unique weapon option for our warships in facing the new defense challenges of the future.