The United States’ Department of Homeland Security (DHS) is a department of the US’ federal government officially created on November 27, 2002 by the Homeland Security Act at the initiative of President George W. Bush, in response to the September 11, 2001 attacks.
Its purpose is to organize and ensure the country’s internal security; it encompasses agencies previously under the direction of other departments of the federal administration and is headed by the United States Secretary of Homeland Security, Kevin McAleenan, acting since 2019, as a member of the presidential cabinet. This is the largest restructuring of the US government since the creation of the Department of Defense in 1947.
The department also benefits from the support of the intelligence community agencies (CIA, NSA and FBI in particular). Responsible for counter-intelligence within the United States, among other things, the Department has great investigative powers, which are reflected in the USA PATRIOT Act.
ESTA is then required to all nationals of the Visa Waiver Program countries