united states
England
Austria-Hungary was the first nation to declare war in the Great War, also known as World War I. On July 28, 1914, it declared war on Serbia following the assassination of Archduke Franz Ferdinand. This declaration set off a chain reaction of alliances and mobilizations that escalated the conflict into a full-scale war involving multiple nations.
Austria-Hungary
England
Yes every nation does. Due to the laws of war this is neccesary
Since the nation of Afghanistan is still at war, it may be premature to declare the war a success.
In both.
No.
germany
no
Any country can declare war on anybody else. What matters is can you back it up?