	Introduction

There is consensus that border security is a pivotal function in protecting the American people from terrorists and their instruments of destruction. This report utilizes several graphical presentations to better understand the points of vulnerability in the border security system, before discussing one, integrated approach. This report is the first in a three-part series of CRS reports that make use of analytical frameworks to better understand complex problems in border security and cast them in terms that facilitate the consideration of alternative policies and practices. (CRS Report RL32840, Border and Transportation Security: Selected Programs and Policies , the second report in the series discusses selected programs and policies currently in place to address these issues. The third and final report in the series addresses possible approaches and policy options that might be explored by Congress in searching for higher levels of border security, and is entitled CRS Report RL32841, Border and Transportation Security: Possible New Directions and Policy Options .) The Role of Border Security in Homeland Security

The homeland security effort can be seen as a series of concentric circles or screens, with the outer screen being that of preventive efforts launched outside the country. In the immediate aftermath of September 11, 2001, the borders of the United States were essentially shut down. If the border is envisioned not merely as a physical boundary but rather as a flexible concept that allows for the possibility that the border begins at the point where goods or people commence their U.S.-bound journey, a significantly wider array of options for border management policies becomes available. What follows are a series of conceptualizations intended to assist in answering the above questions and when combined with a discussion of current border policies, may be useful in seeking new directions for more effective border management policies. Internationally shipped cargoes travel in various conveyances on a variety of infrastructures, through a number of places, are held in the custody of numerous people and organizations, and can involve up to 40 separate documents to complete the journey from the source zone to the distribution zone. Conclusion

Achieving adequate border security is an extremely complex task. The conceptual frameworks outlined in this report are meant to assist the policy maker in understanding the legitimate flows of people and goods entering the country.
Border security is a pivotal function in protecting the American people from terrorists and their instruments of destruction. This report uses a series of graphical presentations to form one possible framework that might assist policy makers in understanding the complex nature of border security. It is the first in a three-part series of CRS reports that make use of analytical frameworks to better understand complex problems in border security and cast them in terms that facilitate the consideration of alternative policies and practices. (CRS Report RL32840, Border and Transportation Security: Selected Programs and Policies, the second report in the series discusses selected programs and policies currently in place to address these issues. The third and final report in the series is CRS Report RL32841, Border and Transportation Security: Possible New Directions and Policy Options.)
Border security is an important component of the overall homeland security effort. This effort can be seen as a series of concentric circles or screens, with the outer screen being that of preventative efforts launched outside the country-for example, interdicting or arresting terrorists and their weapons abroad before they reach the United States. The next screen is interdiction in the border security system. This series of screens then moves through progressively smaller circles ending with emergency preparedness and response. Congressional concern over homeland security began with broadly defined efforts to learn more about the nature of the terrorist threat, and then moved to much more specific actions following the attacks on September 11, 2001. Congressional interest continues, however, in broader, more strategic approaches.
The search for enhanced border security is a complex task. For example, internationally shipped cargoes travel in various conveyances on a variety of infrastructures, through a number of places, are held in the custody of numerous people and organizations, and can involve up to 40 separate documents to complete the journey from the source zone to the distribution zone. This report suggests that if the border can be envisioned not merely as a physical boundary but rather as a flexible concept that allows for the possibility that the border begins at the point where goods or people commence their U.S.-bound journey, a significantly wider array of options for border management policies becomes available.
What follows are a series of graphical presentations intended to assist policy makers in visualizing the flow of people and goods across the borders that, when combined with a discussion of current border policies (discussed in the second report in this series), may be useful in seeking new directions for more effective border management policies (discussed in the third and final report in the series). This report will not be updated.