U.S. Department of Defense

Overview

The United States Department of Defense is the federal department that provides the military forces needed to deter war and protect the nation’s security, headquartered at the Pentagon in Arlington, Virginia (Office of the Under Secretary of Defense (Comptroller)). It is the country’s largest employer, with more than 2.1 million military service members and over 770,000 civilian employees; the Pentagon building itself holds about 26,000 people and 17.5 miles of hallways (Office of the Under Secretary of Defense (Comptroller)). The lineage runs back to the Continental Congress’s creation of the Army, Navy, and Marine Corps in 1775, through the Department of War (1789) and the Department of the Navy (1790), to the National Security Act of 1947 and its 1949 amendments, which built the modern department and created the Chairman of the Joint Chiefs of Staff (Office of the Under Secretary of Defense (Comptroller)). In 2019 Congress established the Space Force, the newest military service, under the Department of the Air Force (Office of the Under Secretary of Defense (Comptroller)).

It is led by Secretary Pete Hegseth, a former Fox News host and Army National Guard veteran confirmed January 24, 2025 by a 51–50 Senate vote — Record Vote 15 (Congress.gov) (Al Jazeera).

Three stories define the department in this profile: its split-court legal fight with the AI company Anthropic, the executive order that brought back the War Department name as a secondary title, and the Iran war that has driven impeachment pressure against Hegseth.

The Anthropic blacklist

In March 2026, Hegseth designated Anthropic a national security supply chain risk — effectively blacklisting the startup from military contracts — under two different laws. The designation came after months of failed negotiations and public recriminations over the company’s refusal to remove its guardrails against autonomous weapons and mass domestic surveillance (Defense News).

The root of the dispute was a contract disagreement. The department had sought access to Anthropic’s Claude chatbot for “all lawful uses”; Anthropic, whose published policies rule out lethal autonomous warfare without meaningful human oversight and mass surveillance of U.S. citizens, refused to drop those restrictions (Mathrubhumi). CEO Dario Amodei said AI is not yet reliable enough to be deployed in autonomous weapons and called mass surveillance of U.S. citizens a rights violation the company would not support (Mathrubhumi). Anthropic told the court it could not in good conscience remove protections against autonomous targeting of civilians (Defense News).

Anthropic said the designation cost it billions of dollars and damaged its reputation ahead of a planned initial public offering, and it sued (Defense News).

Two courts, two answers

The same designation produced opposite judicial outcomes. In August 2026, Judge Rita F. Lin in San Francisco struck down a parallel designation of Anthropic made under a different law. She found the blacklisting was unlawful retaliation for the company’s AI-safety views, in violation of the First Amendment, and that the department had violated due process by giving no advance notice, no evidence, and no opportunity to respond, bypassing the statutory procedures Congress had set out. “The empty invocation of national security is not a blank check to punish and retaliate against government critics,” Lin wrote (Mathrubhumi). Lin also blocked a separate government-wide ban on Anthropic and Hegseth’s order barring military contractors from doing business with the startup (Defense News).

Then, on September 25, 2026, the D.C. Circuit ruled 2–1 the other way, upholding the blacklisting. The majority said it was reasonable to designate the startup after it refused to let its products be used for autonomous weapons or mass surveillance, and it rejected Anthropic’s claim that the move was retaliation for the company’s speech (Defense News).

The majority opinion, written by Judge Gregory Katsas, credited Hegseth’s argument about operational risk: “The Secretary raises the deeply sobering prospect of overly constrained AI models shutting down unexpectedly and thus causing important military operations to fail” (Defense News). The ruling was a win for Hegseth and for the Trump administration, which has embraced AI in military planning and pressed companies to do business with the Pentagon on its terms (Defense News). Anthropic, which said it disagreed with the decision, told Reuters it was considering asking the full appeals court to review the ruling (Defense News).

The two rulings sit under different statutes: the D.C. Circuit upheld the designation under one law while Lin struck down the parallel designation under another, because Hegseth had designated Anthropic under two different laws after the failed negotiations. The blacklisting’s survival therefore depends on which legal authority is being challenged (Defense News).

The “Department of War” title

On September 5, 2025, President Trump signed an executive order authorizing “Department of War” as a secondary title for the Department of Defense. The legal name of the department stays the Department of Defense; a full rename would require an act of Congress (Reuters).

The order changed the branding anyway. The department’s website address shifted from defense.gov to war.gov the same day it was signed, Hegseth’s office door sign was changed to read “Secretary of War,” and the gold letters spelling “Secretary of Defense” were removed from outside his office (Reuters) (Associated Press). On November 13, 2025, Hegseth installed a bronze “Department of War” plaque at the Pentagon’s entrance (Army Times). Trump said he wanted the name “to project strength and resolve,” citing the Allied victories in the First and Second World Wars, and complained the “Department of Defense” name was “woke” (Reuters) (Associated Press). The order’s stated rationale was that the name “conveys a stronger message of readiness and resolve compared to ‘Department of Defense,’ which emphasizes only defensive capabilities” (Army Times).

The rebrand’s price tag

The Congressional Budget Office estimated in January 2026 that the rebrand could cost taxpayers up to $125 million if implemented broadly and rapidly throughout the department, about $10 million for a “modest implementation” centered in the secretary’s office, and “hundreds of millions of dollars” for a full statutory renaming — with significant uncertainty because the department had not provided implementation details (Associated Press). The CBO analysis was requested by Senate Democratic Leader Chuck Schumer and Senator Jeff Merkley (Associated Press). The Pentagon’s own April 2026 legislative proposal to codify the name put the figure at approximately $52.5 million: $44.6 million for defense agencies and field activities, $3.5 million for the military departments, $3 million for the secretary’s office and Washington Headquarters Services, and $400,000 for the Joint Staff, combatant commands, and National Guard Bureau (Army Times). The proposal said the changes were already implemented in 2026 and would have “no significant impact” on the 2027 budget (Army Times).

A permanent rename has little momentum: Senators Mike Lee, Rick Scott, and Marsha Blackburn introduced a bill to make it official, but it has not progressed and Congress has shown no serious interest (Associated Press). The House approved the rename in July 2026 as part of its version of the Fiscal Year 2027 National Defense Authorization Act; the Senate has yet to act (CNA).

Hegseth’s Pentagon

Hegseth’s tenure has been marked by friction almost from the start. In March 2025, he was drawn into the “Signalgate” controversy after a journalist was accidentally added to a Signal chat in which Hegseth and other officials discussed strikes on Yemen’s Houthis; the Pentagon’s inspector general later found policy violations (Al Jazeera).

The personnel churn followed quickly: the firings of Chief of Naval Operations Adm. Lisa Franchetti, Coast Guard Commandant Linda Fagan, and Joint Chiefs Chairman Gen. Charles Q. Brown, the forced-out resignation of Army Secretary Dan Driscoll, and the removal of some 80 names from military promotion lists (Al Jazeera). On the policy side, the department sought a record $1.5 trillion budget request for fiscal 2027, pushed force restructuring and drone acquisition, and oversaw strikes on suspected drug-smuggling boats in the Caribbean that drew international criticism (Al Jazeera). The department has also prosecuted the war with Iran that began in February 2026, the conflict that has shaped much of Hegseth’s tenure (Al Jazeera).

The Iran war and the impeachment punt

Since February 2026 the United States has been embroiled in a war on Iran, with Hegseth boasting of unleashing the military to use “maximum authorities on the battlefield” — understood as a loosening of the combat rules meant to protect civilians (Al Jazeera). On the war’s first day, a U.S. Tomahawk missile struck an Iranian elementary school, killing an estimated 170 people, mostly children; Iranian officials later accused the U.S. of hitting a civilian wedding in Kuhestak, killing at least five and wounding more than 60 (Al Jazeera). The war stretches into its seventh month with criticism that Hegseth has no clear exit strategy, and it has contributed to a surge in oil prices (Al Jazeera). In July, Hegseth told the Senate Appropriations Committee that $37.5 billion had been spent on the war so far, above the $25 billion estimate the department gave in April (Al Jazeera). The night before the impeachment articles were introduced, seven House Republicans voted for a symbolic measure to end the Iran war — the third House rebuke of Trump over the conflict (USA Today).

On September 15, 2026, Representative Thomas Massie introduced articles of impeachment against Hegseth over the Iran war (USA Today). The next day, House Republicans abruptly canceled their last day of work before a roughly eight-week recess, punting any impeachment vote until after the November midterm elections (USA Today). Speaker Mike Johnson said the scheduling was unrelated and called the resolution a “publicity stunt” that “will immediately be tabled” when the House returns; Democrats said Republicans were afraid the House would vote to impeach (USA Today).

What this profile does not claim

• It does not state the specific charges or statutory allegations in Rep. Massie’s impeachment articles; only their existence, date, and the punted vote are verified here.
• It does not treat “Department of War” as the department’s legal name: the House approved the rename in July 2026 via the FY2027 NDAA but the Senate has yet to act, so the permanent name remains Department of Defense.
• It does not cover the reported June 2026 export-control directive disabling Anthropic models across the executive branch; that belongs to the executive-branch entity, not this profile.
• It does not state the final outcome of the California case after Judge Lin’s August 2026 ruling.
• It does not name the current deputy secretary, Joint Chiefs chairman, or service-branch leadership; they were not verified from full-read sources this session.
• It does not duplicate the full Anthropic company profile; the startup’s own story belongs to its own profile.