U.S. Department of Defense in the context of "Ready Reserve"

The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South Pacific Ocean, and Indian Ocean for all branches of the U.S. Department of Defense and other U.S. government agencies. Their warnings are intended primarily for the protection of U.S. military ships and aircraft, as well as military installations jointly operated with other countries around the world. Its U.S. Navy components are aligned with the Naval Meteorology and Oceanography Command.

The New York Institute of Technology (NYIT or New York Tech) is a private research university with two main campuses in New York, one in Old Westbury, on Long Island, and one on the Upper West Side in Manhattan. The university was founded in 1955. In addition to its main campuses, it has a cybersecurity research lab, a biosciences and bioengineering lab, Nassau County's first Class 10,000 clean room for nanoengineering, and the Entrepreneurship and Technology Innovation Center, which has close links to NASA, in Old Westbury, as well as campuses in Arkansas, China, and Canada. The U.S. Department of Defense and the U.S. Department of Homeland Security designated NYIT as a National Center of Academic Excellence in Cyber Defense Education.

NYIT has over 100 undergraduate and graduate degree programs. It awards bachelor's, master's and doctoral degrees for the completion of these programs. It has five schools and two colleges, all with an emphasis on technology and applied scientific research. NYIT's 2025 Carnegie Classification has been designated as a Mixed Undergraduate/Graduate-Doctorate Medium.

Assistant Secretary of Defense is a title used for many high-level executive positions in the Office of the Secretary of Defense within the U.S. Department of Defense. The Assistant Secretary of Defense title is junior to Under Secretary of Defense. Reorganization Plan No. 6 of 30 June 1953 increased the number of assistant secretaries. The National Defense Authorization Act for Fiscal Year 2023 added three new Assistant Secretary positions under the Under Secretary for Research and Engineering. The list of Assistant Secretaries of Defense includes:

• Office of the Under Secretary of Defense for Personnel and Readiness
  1. Assistant Secretary of Defense for Health Affairs
  2. Assistant Secretary of Defense for Manpower and Reserve Affairs
  3. Assistant Secretary of Defense for Readiness
• Office of the Under Secretary of Defense for Acquisition and Sustainment
  1. Assistant Secretary of Defense for Acquisition
  2. Assistant Secretary of Defense for Energy, Installations, and Environment
  3. Assistant Secretary of Defense for Sustainment
  4. Assistant Secretary of Defense for Nuclear, Chemical, and Biological Defense Programs
  5. Assistant Secretary of Defense for Industrial Base Policy
• Office of the Under Secretary of Defense for Policy
  1. Assistant Secretary of Defense for Homeland Defense and Hemispheric Affairs
  2. Assistant Secretary of Defense for Indo-Pacific Security Affairs
  3. Assistant Secretary of Defense for Cyber Policy
  4. Assistant Secretary of Defense for Special Operations/Low Intensity Conflict & Interdependent Capabilities
  5. Assistant Secretary of Defense for Strategy, Plans, and Capabilities
  6. Assistant Secretary of Defense for International Security Affairs
• Office of the Under Secretary of Defense for Research and Engineering
  1. Assistant Secretary of Defense for Science and Technology
  2. Assistant Secretary of Defense for Critical Technologies
  3. Assistant Secretary of Defense for Mission Capabilities.
• Reports to the Secretary of Defense
  1. Assistant Secretary of Defense for Legislative Affairs

Former Assistant Secretary of Defense positions include:

"There are unknown unknowns" is a phrase from a response United States Secretary of Defense Donald Rumsfeld gave to a question at a U.S. Department of Defense (DoD) news briefing on February 12, 2002, about the lack of evidence linking the government of Iraq with the supply of weapons of mass destruction to terrorist groups. Rumsfeld stated:

The statement became the subject of much commentary. In The Decision Book (2013), author Mikael Krogerus (de) refers to it as the "Rumsfeld matrix". The statement also features in a 2013 documentary film, The Unknown Known, directed by Errol Morris.