The Russian-Ukrainian war has lasted for more than 600 people, with more than one million people mobilized on both sides, and hundreds of thousands of dead and wounded.
The reason is simple, neither side has declared war.
Russia has not declared war on Ukraine, and Ukraine has not declared war on Russia.
The official statement is that Russia calls it a special military operation, and Ukraine calls it a wartime state,
The definition of war in international law generally begins with the declaration of war and ends with the conclusion of a peace treaty, so the two countries are not legally in a state of war.
But there is information that Ukraine will declare war on Russia this fall, and the scale of the war will be further expanded by then.