"Defend potential targets of attack. Our enemies are opportunistic, exploiting vulnerabilities and seeking alternatives to those targets with increased security measures. The targeting trend since at least September 11 has been away from hardened sites, such as official government facilities with formidable security, and toward softer targets – schools, restaurants, places of worship, and nodes of public transportation – where innocent civilians gather and which are not always well secured. Specific targets vary, but they tend to be symbolic and often selected because they will produce mass casualties, economic damage, or both.

"While it is impossible to protect completely all potential targets all the time, we can deter and disrupt attacks, as well as mitigate the effects of those that do occur, through strategic security improvements at sites both at home and overseas. Among our most important defensive efforts is the protection of critical infrastructures and key resources – sectors such as energy, food and agriculture, water, telecommunications, public health, transportation, the defense industrial base, government facilities, postal and shipping, the chemical industry, emergency services, monuments and icons, information technology, dams, commercial facilities, banking and finance, and nuclear reactors, materials, and waste. These are systems and assets so vital that their destruction or incapacitation would have a debilitating effect on the security of our Nation. We will also continue to protect various assets such as historical attractions or certain high-profile events whose destruction or attack would not necessarily debilitate our national security but could damage the morale and confidence of the American people. Beyond the Homeland, we will continue to protect and defend U.S. citizens, diplomatic missions, and military facilities overseas, as well as work with our partners to strengthen their ability to protect their populations and critical infrastructures."