Twenty-five years after the Sept. 11 attacks transformed American life, the Department of Homeland Security stands as one of the most consequential institutions created in their aftermath — and one of the most debated.
Congress established DHS through the Homeland Security Act of 2002, eventually bringing together all or parts of 22 federal agencies and offices. The undertaking represented one of the largest restructurings of the federal government since the creation of the Defense Department. DHS formally began operations in 2003 with a broad mandate encompassing counterterrorism, border security, emergency management, aviation security, infrastructure protection and other missions.
The reorganization grew from an urgent and understandable objective: prevent another mass-casualty terrorist attack on American soil.
A quarter-century later, however, the threats facing the United States have changed dramatically. Foreign terrorist organizations remain a concern, but policymakers must also contend with cyberattacks, infrastructure vulnerabilities, politically motivated violence, emerging technologies, transnational crime and increasingly contentious debates over immigration enforcement.
At the same time, DHS has become a focal point in disputes over the proper limits of federal power.
That tension raises a larger institutional question: Was the department designed for the security challenges America actually developed — or primarily for the ones Washington feared immediately after 9/11?
The answer begins with three choices made during the department's creation.







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