"Since September 11, all levels of government have cooperated like never before to strengthen aviation and border security, stockpile more medicines to defend against bioterrorism, improve information sharing among our intelligence agencies, and deploy more resources and personnel to protect our critical infrastructure. The changing nature of the threats facing America requires a new government structure to protect against invisible enemies that can strike with a wide variety of weapons. Today no one single government agency has homeland security as its primary mission. In fact, responsibilities for homeland security are dispersed among more than 100 different government organizations. America needs a single, unified homeland security structure that will improve protection against today's threats and be flexible enough to help meet the unknown threats of the future. The President proposes to create a new Department of Homeland Security, the most significant transformation of the U.S. government in over a half-century by largely transforming and realigning the current confusing patchwork of government activities into a single department whose primary mission is to protect our homeland. The creation of a Department of Homeland Security is one more key step in the President's national strategy for homeland security."
Department of Homeland Security: http://www.dhs.gov