declaration of war

declaration of war (plural declarations of war)

1. A formal announcement by a country or other body with military capability that it is in a state of war with another such entity.
   • 2022 January 12, Dr. Joseph Brennan, “Castles: ruined and redeemed by rail”, in RAIL, number 948, page 55:

     Make no mistake, the sway of the railways' mandate in the middle of the 19th century was, in some quarters, a declaration of war on the old.

   • 2023 November, Andrea L. R. Pillai, “Hawks and Doves: Evaluating Presidential Powers and Duties Against Congress's Power to Declare War”, in Duke Law Journal‎^[1], volume 73, number 2, →ISSN, →OCLC, archived from the original on 11 March 2024, page 419:

     Although the Take Care Clause grants the president significant authority to enforce the laws, the duty to take care does not include a power to forbid the execution of the laws. Consequently, the president does not have the authority to disregard Congress’s declaration of war against Country X. On the contrary, the president has an obligation to faithfully execute the declaration of war, even against their own beliefs and wishes.

• act of war