PRINCIPLE OF LAYERED SECURITY

America is connected to the world by networks that ensure the free flow of goods, peoples, services, and ideas. A vital component of the U.S. economy, these networks can also serve as a conduit for pernicious traffic to America’s shores. Conversely, in times of trouble, from natural disasters to pandemics to terrorist attacks, maintaining these networks will be vital to mitigation and recovery. This chapter addresses three of the most important domains through which global networks enter U.S. territory—land, sea, and air—and surveys major homeland security challenges in each of them. The land-domain focuses on the nation’s borders and how related issues of transnational crime and immigration affect their management. The maritime domain includes the seas, coastal and inland waterways, ports, and related maritime infrastructure. Air includes commercial transport, all forms of general aviation, and air defense. Many security analysts call safeguarding these domains “protecting the commons,” ensuring that “common” means of legitimate trade and travel, such as freedom to use the seas, are safe and secure. While discussions on domain security often focus on protecting critical infrastructure, in fact domain security can include the full range of homeland security tasks from early security interests.

AVIATION SECURITY

Like the maritime domain, U.S. airspace is a complex place vital to the national economy but vulnerable to exploitation by terrorists and damage from human-made and natural disasters. Two months after the attacks, Congress enacted the Aviation and Transportation Security Act  which created the Transportation Security Administration, initially as part of the Department of Transportation but later folded into . The  responsible for overseeing commercial and recreational aviation, including commercial airline safety, and inspecting boarding passengers. Other  elements also have air security missions, including the U.S. Coast Guard and, In addition, the Departments of Defense, State, and Transportation have significant responsibilities related to protecting U.S. airspace.

BORDER SECURITY

The federal government has unique and expansive powers regarding both immigration and border security enforcement. A number of laws govern federal authorities here. The Homeland Security Act of 2002, for example, delineates DHS’s responsibilities. The Immigration and Nationality Act defines many legal authorities of Immigration and Customs Enforcement and Customs and Border Protection.

Few issues regarding homeland security are more contentious than border security and immigration. As noted in, concerns over the sovereignty and security of U.S. borders and immigration have waxed and waned over the course of American history. Since, both issues have received significant attention. Today, three components dominate: terrorism, immigration, and transnational crime.

MARITIME SECURITY

The many thousands of miles of U.S. coastline are not only a border, but also a domain vital to the security of the nation. Approximately 95 percent (by volume) of U.S. overseas trade transits the maritime domain. In addition, many major population centers and critical infrastructures are close to U.S. ports or accessible by waterways. The future U.S. maritime environment will be characterized by continued growth in seaborne shipment of energy products, rapid expansion of deep seabed mining, further adoption of containerized shipping, and the continued rise of mega ports as commercial hubs for trans-shipment and deliveries. Maritime security is a complex strategic problem encompassing the physical domain, land-based critical infrastructure, inter modal transportation, and international supply chains that convey goods, services, and passengers. The task is not only safeguarding America’s borders but also ensuring the safety and security of maritime services and activities, as well as nearby populations.

PRINCIPLE OF LAYERED SECURITY

Before World War II, the French military constructed the famed Maginot Line, a series of fortifications and barriers to block traditional invasion routes on the border with Germany. When war broke out, German armies swept through the heavily forested Dearness  following a route the French did not expect and simply bypassing the Maginot Line. Outflanked, French forces fell back and Paris surrendered. The lesson of the Maginot Line holds great relevance for the challenge of protecting the homeland. When it’s not clear exactly how, when, and where defenses are needed, investing the bulk of resources in one predetermined security effort incurs grave risks. U.S. strategy since has viewed the “Maginot Line” approach to homeland security as anathema. Rather, the United States has followed a strategy of “layered security,” relying on a series of programs and initiatives to thwart attacks and mitigate disasters. Securing the perimeter of America is an important layer of the homeland security enterprise.