This publication defines the road ahead for a core mission area identified in the President's National Strategy for Homeland Security-reducing the Nation's vulnerability to acts of terrorism by protecting our critical infrastructures and key assets from physical attack. This publication, the National Strategy for the Physical Protection of Critical Infrastructures and Key Assets, the Strategy, identifies a clear set of national goals and objectives and outlines the guiding principles that will underpin our efforts to secure the infrastructures and assets vital to our national security, governance, public health and safety, economy, and public confidence. This Strategy also provides a unifying organization and identifies specific initiatives to drive our near-term national protection priorities and inform the resource allocation process. Most importantly, it establishes a foundation for building and fostering the cooperative environment in which government, industry, and private citizens can carry out their respective protection responsibilities more effectively and efficiently. This Strategy recognizes the many important steps that public and private entities across the country have taken in response to the September 11, 2001, attacks to improve the security of their critical facilities, systems, and functions. Building upon these efforts, this document provides direction to the federal departments and agencies that have a role in critical infrastructure and key asset protection. It also suggests steps that state and local governments, private sector entities, and concerned citizens across America can take to enhance our collective infrastructure and asset security. In this light, this Strategy belongs and applies to the Nation as a whole, not just to the federal government or its constituent departments and agencies.