The United States must be prepared for a wide variety of low probability attacks on the United States, rather than emphasize any given attack or group of attackers. The United States must plan its Homeland defense policies and programs for a future where there is no way to predict the weapon that will be used or the method chosen to deliver a weapon. This excerpt from the final draft of Homeland Defense discusses the effects of indirect, covert, terrorist, and extremist attacks with chemical, biological, radiological, and nuclear (CBRN) weapons and the Homeland’s defense and response. The report continues with illustrative attack scenarios where different types of CBRN weapons could have lethalities and costs up to several orders of magnitude higher than those that occurred as a result of the World Trade Center, Oklahoma City, and Aum Shinrikyo attacks. The report concludes with a discussion on threat assessment and prioritization. It was stated that there was no way to prioritize which method of CBRN attack could be used in the future, if any. It is more likely that the United States would experience limited attacks as opposed to mass attacks. Also, there are many tactical and technical reasons that biological attacks could become a method of choice. Advances are acknowledged as taking place in the U.S military systems to aid in the detection and response effort. The United States is seen as needing to plan flexibility for a wide spectrum of threats over time. It needs to adapt and evolve its approach to the threat of covert attacks by many. In conclusion, much of the success of Homeland defense will be determined by how the United States reacts and adapts over time after successful attacks. Creating a leak proof defense in a lofty goal. In assessing and prioritizing such threats, there must be an understanding as to how much the world can change after the first attack(s), and how much broader the United States or its allies may come under covert, proxy, or terrorist/extremist attack using weapons of mass destruction. Charts, tables, references