Resolution criteria

This market will resolve to "YES" if a state of declared or undeclared armed conflict exists between the United States and the European Union, or between the United States and any individual member state of the European Union, at any point before 11:59 PM ET on December 31, 2028.

For the purposes of this market, "armed conflict" is defined as a sustained, organized, and intentional use of lethal military force by the armed forces of one party against the other. Minor diplomatic incidents, trade wars, economic sanctions, cyber warfare without physical casualties, or isolated border skirmishes not constituting a broader act of war do not qualify.

Resolution will be based on consensus reporting from major, reputable international news outlets (e.g., Reuters, Associated Press, BBC, The New York Times). In the event of ambiguity, the market will look for official statements from the U.S. Department of State, the European Commission, or the governments of the involved nations confirming the existence of a state of war or active armed conflict.

Background

The United States and the European Union are primary strategic, economic, and military allies, both being members of the North Atlantic Treaty Organization (NATO). The North Atlantic Treaty (the Washington Treaty) establishes a system of collective defense, under which an armed attack against one member is considered an attack against them all. A war between the United States and an EU member state would represent an unprecedented breakdown of the post-WWII transatlantic security architecture.