Order Code RS21899
Updated May 13, 2008
Border Security:
Key Agencies and Their Missions
Blas Nuñez-Neto
Analyst in Social Legislation
Domestic Social Policy Division
Summary
After the massive reorganization of federal agencies precipitated by the creation of
the Department of Homeland Security (DHS), there are now four main federal agencies
charged with securing the United States’ borders: the Bureau of Customs and Border
Protection (CBP), which patrols the border and conducts immigrations, customs, and
agricultural inspections at ports of entry; the Bureau of Immigrations and Customs
Enforcement (ICE), which investigates immigrations and customs violations in the
interior of the country; the United States Coast Guard, which provides maritime and port
security; and the Transportation Security Administration (TSA), which is responsible
for securing the nation’s land, rail, and air transportation networks. This report is meant
to serve as a primer on the key federal agencies charged with border security; as such
it will briefly describe each agency’s role in securing our nation’s borders. This report
will be updated as needed
In the wake of the tragedy of September 11, 2001, the U.S. Congress decided that
enhancing the security of the United States’ borders was a vitally important component
of preventing future terrorist attacks. Before September 11, 2001, border security fell
piecemeal under the mandate of many diverse federal departments, including but not
limited to: the Department of Justice (the Immigration and Naturalization Service); the
Department of the Treasury (the Customs Service); the Department of Agriculture (the
Animal and Plant Health Inspection Service); and the Department of Transportation (the
Coast Guard).
The Homeland Security Act of 2002 (P.L. 107-296) consolidated most federal
agencies operating along the U.S. borders within the newly formed DHS. Most of these
agencies were located in the Directorate of Border and Transportation Security (BTS),
which was charged with securing the borders; territorial waters; terminals; waterways; and
air, land, and sea transportation systems of the United States; and managing the nation’s

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ports of entries.1 The lone exception is the U.S. Coast Guard, which remained a
standalone division within DHS. The BTS was composed of three main agencies: (1) the
CBP, which is charged with overseeing commercial operations, inspections, and land
border patrol functions, (2) ICE, which oversees investigations, alien detentions and
removals, air/marine drug interdiction operations, and federal protective services, and (3)
the TSA, which is charged with protecting the nation’s air, land, and rail transportation
systems against all forms of attack to ensure freedom of movement for people and
commerce.
On July 13, 2005, the Secretary of DHS, Michael Chertoff, announced the results of
the months-long Second Stage Review (2SR) that he undertook upon being confirmed as
DHS Secretary. One of Secretary Chertoff’s main recommendations, which was agreed
to by the DHS Appropriations Conferees, was the elimination of the BTS Directorate.
The Secretary announced the creation of a new Directorate of Policy (subject to legislative
approval), which would, among other things, assume the policy coordination
responsibilities of the BTS Directorate. The operational agencies that comprised BTS
(CBP, ICE, TSA) will now report directly to the Secretary and Deputy Secretary of DHS.
The goal of this reorganization is to streamline the policy creation process and ensure that
DHS policies and regulations are consistent across the department. Additionally, the
Federal Air Marshals program was moved out of ICE and back into TSA to increase
operational coordination between all aviation security entities in the department.
Conceptually speaking, CBP provides the front line responders2 to immigrations and
customs violations and serves as the law enforcement arm of DHS, while ICE serves as
the investigative branch. TSA is charged with securing the nation’s transportation
systems, whereas the U.S. Coast Guard also serves an important border security function
by patrolling the nation’s territorial and adjacent international waters against foreign
threats. Combined FY2008 appropriations for BTS and the Coast Guard equaled $26.9
billion,3 whereas the combined full time equivalent (FTE) manpower totaled 167,784
employees.4
The Bureau of Customs and Border Protection (CBP)
CBP combined all the previous border law enforcement agencies under one
administrative umbrella. This involved absorbing employees from the Immigration and
Naturalization Service (INS), the Border Patrol, the Customs Service, and the Department
1 For a more detailed information on DHS, see CRS Report RL31549, Department of Homeland
Security: Consolidation of Border and Transportation Security Agencies, by Jennifer Lake.
2 Some argue that the State Department’s Consular posts abroad provide the first line of defense
by reviewing visa applications and determining which foreign nationals will be provided with the
documentation required to legally enter the country.
3 This number, and all the budget numbers in the body of this report, represents the department’s
net appropriation. For a more detailed breakdown of DHS appropriations for FY2008, including
the gross budget authority provided to each agency, see CRS Report RL34482, Homeland
Security Department: FY2009 Request, Jennifer Lake and Blas Nuñez-Neto, Coordinators.
4 All manpower estimates taken from The Department of Homeland Security, Congressional
Budget Justification, Department of Homeland Security Fiscal Year 2009.

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of Agriculture. CBP’s mission is to prevent terrorists and terrorist weapons from entering
the country, provide security at U.S. borders and ports of entry, apprehend illegal
immigrants, stem the flow of illegal drugs, and protect American agricultural and
economic interests from harmful pests and diseases.5 As it performs its official missions,
CBP maintains two overarching and sometimes conflicting goals: increasing security
while facilitating legitimate trade and travel.6 In FY2008, CBP’s appropriated net budget
authority totaled $9.42 billion7 and manpower totaled 50,417 FTE.
Between official ports of entry, the U.S. Border Patrol (USBP) enforces U.S.
immigration law and other federal laws along the border. As currently comprised, the
USBP is the uniformed law enforcement arm of the Department of Homeland security.
Its primary mission is to detect and prevent the entry of terrorists, weapons of mass
destruction, and unauthorized aliens into the country, and to interdict drug smugglers and
other criminals. The USBP is thus vitally important to our nation’s defense against
terrorists and all others attempting to enter goods or persons into the country illegally. In
the course of discharging its duties the USBP patrols over 8,000 miles of our international
borders with Mexico and Canada and the coastal waters around Florida and Puerto Rico.
At official ports of entry, CBP officers are responsible for conducting immigrations,
customs, and agricultural inspections on entering aliens. As a result of the new “one face
at the border” initiative, CBP inspectors are being cross-trained to perform all three types
of inspections in order to streamline the border crossing process. This initiative unifies
the prior inspections processes, providing entering aliens with one primary inspector who
is trained to determine whether a more detailed secondary inspection is required.8
CBP inspectors enforce immigration law by examining and verifying the travel
documents of incoming international travelers to ensure they have a legal right to enter
the country. On the customs side, CBP inspectors ensure that all imports and exports
comply with U.S. laws and regulations, collect and protect U.S. revenues, and guard
against the smuggling of contraband. Additionally, CBP is responsible for conducting
agricultural inspections at ports of entry in order to enforce a wide array of animal and
plant protection laws. In order to carry out these varied functions, CBP inspectors have
a broad range of powers to inspect all persons, vehicles, conveyances, merchandise, and
baggage entering the United States from a foreign country.9
To execute its various missions, CBP maintains and utilizes several databases. CBP
also administers the U.S. Visitor and Immigrant Status Indicator Technology (US-VISIT)
5 U.S. Congress, House Appropriations Committee, Department of Homeland Security
Appropriations Bill, 2005, 108th Cong., 2nd sess., H.Rept. 108-541.
6 U.S. Customs and Border Protection, Performance and Annual Report: Fiscal Year 2003, p. 25.
7 The gross budget authority appropriated for CBP in FY2008 equaled $10.83 billion.
8 Department of Homeland Security, Office of the Press Secretary, “Homeland Security
Announces New Initiatives,” press release, September 2, 2003.
9 For a more detailed analysis of inspections practices along the U.S. border, including the
legislative foundation for CBP powers, a history of inspections practices, and the policy issues
involved, refer to CRS Report RL32399, Border Security: Inspections Practices, Policies, and
Issues, by Ruth Ellen Wasem, coordinator.

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program, which requires all incoming non-immigrant aliens to submit to a biometric
scan.10 Additionally, CBP administers the Container Security Initiative, a program in
which CBP inspectors pre-screen U.S.-bound marine containers at foreign ports of
loading around the world.
Bureau of Immigrations and Customs Enforcement (ICE)
ICE merged the investigative functions of the former INS and the Customs Service,
the INS detention and removal functions, most INS intelligence operations, and the
Federal Protective Service This makes ICE the principal investigative arm for DHS.
ICE’s mission is to detect and prevent terrorist and criminal acts by targeting the people,
money, and materials that support terrorist and criminal networks.11 As such they are an
important component of our nation’s border security network even though their main
focus is on interior enforcement. In FY2008, ICE appropriations totaled $4.74 billion,12
and the agency had 17,938 FTE employees.
Unlike CBP, whose jurisdiction is confined to law enforcement activities along the
border, ICE special agents investigate immigrations and customs violations in the interior
of the United States. ICE’s mandate includes uncovering national security threats such
as weapons of mass destruction or potential terrorists, identifying criminal aliens for
removal, probing immigration-related document and benefit fraud, investigating work-site
immigration violations, exposing alien and contraband smuggling operations, interdicting
narcotics shipments,13 and detaining illegal immigrants and ensuring their departure (or
removal) from the United States.14 ICE is also responsible for the collection, analysis and
dissemination of strategic and tactical intelligence data pertaining to homeland security,
infrastructure protection, and the illegal movement of people, money, and cargo within
the United States.15 Lastly, ICE polices and secures more than 8,800 federal facilities
nationwide via the Federal Protective Service.16
The United States Coast Guard
The Coast Guard was incorporated into DHS as a standalone agency in 2002. Their
overall mission is to protect the public, the environment, and U.S. economic interests in
10 For further discussion and analysis of the US-VISIT program, see CRS Report RL32234, U.S.
Visitor and Immigrant Status Indicator Technology Program (US-VISIT), by Lisa Seghetti.
11 Bureau of Immigrations and Customs Enforcement, Border Security and Immigration
Enforcement Fact Sheet, at [http://www.ice.gov/graphics/news/factsheets/061704det_FS.htm].
12 The gross budget authority appropriated for ICE in FY2008 equaled $5.58 billion.
13 Bureau of Immigrations and Customs Enforcement, Office of Investigations Fact Sheet,
[http://www.ice.gov/graphics/news/factsheets/investigation_FS.htm].
1 4 Bureau of Immigrations and Customs Enforcement Organization, at
[http://www.ice.gov/graphics/about/organization/index.htm].
15 Bureau of Immigrations and Customs Enforcement, Office of Intelligence Organization, at
[http://www.ice.gov/graphics/about/organization/org_intell.htm].
1 6 Bureau of Immigrations and Customs Enforcement, Organization, at
[http://www.ice.gov/graphics/about/organization/index.htm].

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maritime regions — at the nation’s ports and waterways, along the coast, and in
international waters.17 The Coast Guard is thus the nation’s principal maritime law
enforcement authority and the lead federal agency for the maritime component of
homeland security, including port security. Among other things, the Coast Guard is
responsible for: evaluating, boarding, and inspecting commercial ships as they approach
U.S. waters; countering terrorist threats in U.S. ports; and for helping to protect U.S. Navy
ships in U.S. ports. A high-ranking Coast Guard officer in each port area serves as the
Captain of the Port and is the lead federal official responsible for the security and safety
of the vessels and waterways in their geographic zone.18 In FY2008, Coast Guard net (and
gross) appropriated budget authority totaled $8.63 billion, and the agency had 48,558 FTE
military and civilian employees.
As part of Operation Noble Eagle (military operations in homeland defense and civil
support to U.S. federal, state and local agencies), the Coast Guard is at a heightened state
of alert protecting more than 361 ports and 95,000 miles of coastline. The Coast Guard’s
homeland security role includes protecting ports, the flow of commerce, and the marine
transportation system from terrorism; maintaining maritime border security against illegal
drugs, illegal aliens, firearms, and weapons of mass destruction; ensuring that the U.S. can
rapidly deploy and resupply military assets by maintaining the Coast Guard at a high state
of readiness as well as by keeping marine transportation open for the other military
services; protecting against illegal fishing and indiscriminate destruction of living marine
resources; preventing and responding to oil and hazardous material spills; and
coordinating efforts and intelligence with federal, state, and local agencies.19
The Transportation Security Administration (TSA)
The TSA was created as a direct result of the events of September 11 and is charged
with protecting the United States’ air, land, and rail transportation systems to ensure
freedom of movement for people and commerce. The Aviation and Transportation
Security Act (ATSA, P.L. 107-71) created the TSA and included provisions that
established a federal baggage screener workforce, required checked baggage to be
screened by explosive detection systems, and significantly expanded FAMS. In 2002,
TSA was transferred to the newly formed DHS from the Department of Transportation;
as previously noted, in 2003 the Federal Air Marshal program was taken out of TSA and
transferred to ICE. In FY2006, the program was transferred back to TSA. In FY2008,
TSA appropriations totaled $4.11 billion,20 and the agency had 50,871 FTE employees.
To achieve its mission of securing the nation’s aviation, TSA assumed responsibility
for screening air passengers and baggage — a function that had previously resided with
17 U.S. Coast Guard, Overview at [http://www.uscg.mil/overview/].
18 For an in depth discussion of the Coast Guard and port security, see CRS Report RS21125,
Homeland Security: Coast Guard Operations — Background and Issues for Congress, by Ronald
O’Rourke, and CRS Report RL31733, Port and Maritime Security: Background and Issues for
Congress, by John Frittelli.
19 U.S. Coast Guard, Homeland Security Factcard, at [http://www.uscg.mil/hq/g-cp/comrel/
factfile/Factcards/Homeland.htm].
20 The gross budget authority appropriated for the TSA in FY2008 equaled $6.82 billion.

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the air carriers. TSA is also charged with ensuring the security of air cargo and
overseeing security measures at airports to limit access to restricted areas, secure airport
perimeters, and conduct background checks for airport personnel with access to secure
areas, among other things.21 However, an opt out provision in ATSA will permit every
airport with federal screeners to request a switch to private screeners commencing in
November 2004.22 Additionally, as a result of the 2SR, the Federal Air Marshals program
has been transferred back to TSA. FAMS is responsible for detecting, deterring and
defeating hostile acts targeting U.S. air carriers, airports, passengers and crews by placing
undercover armed agents in airports and on flights.
Conclusion
This report has briefly outlined the roles and responsibilities of the four main
agencies within the DHS charged with securing our nation’s borders: the CBP, ICE, the
U.S. Coast Guard, and the TSA. It should be noted, however, that although the Homeland
Security Act of 2002 consolidated all the agencies with primary border security roles in
DHS, many other federal agencies are involved in the difficult task of securing our
nation’s borders. Although border security may not be in their central mission, they
nevertheless provide important border security functions. These agencies include, but are
not limited to the Bureau of Citizenship and Immigrations Services within DHS, which
processes permanent residency and citizenship applications, as well as asylum and refugee
processing; the Department of State, which is responsible for visa issuances overseas; the
Department of Agriculture, which establishes the agricultural policies that CBP Inspectors
execute; the Department of Justice, whose law enforcement branches (the Federal Bureau
of Investigation and Drug Enforcement Agency) coordinate with CBP and ICE agents
when their investigations involve border or customs violations; the Department of Health
and Human Services, through the Food and Drug Administration and the Center for
Disease Control; the Department of Transportation, whose Federal Aviation
Administration monitors all airplanes entering American air space from abroad; the
Treasury Department, whose Bureau of Alcohol, Tobacco, and Firearms investigates the
smuggling of guns into the country; and lastly the Central Intelligence Agency, which is
an important player in the efforts to keep terrorists and other foreign agents from entering
the country. Additionally, due to their location, state and local responders from
jurisdictions along the Canadian and Mexican borders also play a significant role in the
efforts to secure our nation’s borders.
21 U.S. General Accounting Office, Aviation Security: Efforts to Measure Effectiveness and
Address Challenges, GAO-04-232T, November 5, 2003, pp. 5-6.
22 See CRS Report RL32383, A Return to Private Security at Airports?: Background and Issues
Regarding the Opt-Out Provision of the Aviation and Transportation Security Act, by
Bartholomew Elias.

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