This second edition urges policymakers to focus on filling key gaps that remain in the current homeland security effort in 2003: identifying better protection for private infrastructure; using information technology to share intelligence and more effectively ''connect the dots'' that could hold hints to possible terrorist tactics; expanding the capacities of the coast guard and customs service, as well as airline transportation security; dealing with the possible threat of surface-to-air missiles to airliners; and encouraging better co-ordination among intelligence agencies. While acknowledging the impossibility of preventing every possible type of terrorist violence, the authors recommend a more systematic approach to homeland security that focuses on preventing attacks that can cause a large number of casualties, massive economic or societal disruption, or severe political harm to the nation.