"Declared war" means that a country formally announces or proclaims its intent to engage in armed conflict with another nation. It marks a significant escalation in hostilities between countries.
Related terms
Neutrality: A policy where a country does not take sides or involve itself in wars between other nations.
Treaty: A formal agreement between two or more countries, often used to establish peace after conflicts.
Alliances: When multiple countries join together for mutual defense or support during times of war or crisis.