As part of its mission, the Department of Homeland Security (DHS), through its U.S. Customs and Border Protection (CBP) component, is to secure U.S. borders against threats of terrorism; the smuggling of drugs, humans and other contraband; and illegal migration. At the end of fiscal year 2010, DHS investments in border security had grown to $11.9 billion and included more than 40,000 personnel. To secure the borders, DHS coordinates with federal, state, local, tribal, and Canadian partners. This book examines DHS progress and challenges in securing the U.S. Southwest and Northern borders with a focus on enhancing measures to protect against the entry of terrorists, inadmissible aliens, and contraband; improving interagency coordination; and strengthening technology acquisition and deployment plans.