> War is an act of diplomacy, but what Russia has been doing is anything but.
No, this is an unnecessary formalism. Why not define war by what is actually happening (large scale armed conflict between states or other large groups) rather than by mere words uttered by somebody?
> In his study Hostilities without Declaration of War (1883), the British scholar John Frederick Maurice showed that between 1700 and 1870 war was declared in only 10 cases, while in another 107 cases war was waged without such declaration (these figures include only wars waged in Europe and between European states and the United States, not including colonial wars in Africa and Asia).
> The principle of a compulsory declaration of war has now fallen into disuse. In practice and under customary law, a declaration of war is no longer necessary for a state of war to exist; it suffices for one of the parties to make its intentions clear by actually commencing hostilities. Similarly, a formal declaration of war is not necessary for the application of international humanitarian law.
>> In practice and under customary law, a declaration of war is no longer necessary for a state of war to exist
Was it ever? Under customary law, a state of war exists between any two parties by default. What needs to be declared is peace, which is why so many ancient peace treaties survive.
No, this is an unnecessary formalism. Why not define war by what is actually happening (large scale armed conflict between states or other large groups) rather than by mere words uttered by somebody?
> In his study Hostilities without Declaration of War (1883), the British scholar John Frederick Maurice showed that between 1700 and 1870 war was declared in only 10 cases, while in another 107 cases war was waged without such declaration (these figures include only wars waged in Europe and between European states and the United States, not including colonial wars in Africa and Asia).
See also e.g. Red Cross: https://casebook.icrc.org/a_to_z/glossary/declaration-war
> The principle of a compulsory declaration of war has now fallen into disuse. In practice and under customary law, a declaration of war is no longer necessary for a state of war to exist; it suffices for one of the parties to make its intentions clear by actually commencing hostilities. Similarly, a formal declaration of war is not necessary for the application of international humanitarian law.