In late Year 18, Napoleon / Hitler / Bin Laden first announced his international war coalition . . .
That constituted a declaration of war against Russia and the world's most powerful nation, the leading Western empire. In late 1806, Napoleon first announced his Continental System, a warmongering alliance of European nations . . .
Committed to a nation-busting economic embargo of Great Britain, the world's most dominant nation. This new belligerent coalition accordingly demanded that Russia cease its vital trade with Britain, collectively constituting an international trade dispute that would bring Great Britain, the United States and Russia into Napoleon's war in 1812. In late 1936, Hitler first announced his Axis Powers alliance on the cornerstone of the Anti-Communist International Pact, a war coalition among Germany, Japan and Italy (who would officially join in the following year) that would soon after be formalized as the Tripartite Pact. Hitler's declaration of the Anti-Comintern Pact occurred under the auspices of Benito Mussolini's own declaration of an Axis Powers alliance between Germany and Italy a month earlier.
The creation of the Axis Powers alliance marked the failure of the Franco-British Stresa Front alliance, an attempt to ally with Italy and Austria to restrain Hitler's military adventurism, signaling a monumental reversal in the balance of power in Europe that allowed German imperial expansion to march inevitably to war three years later against the world's leading empires, Great Britain and France. The cornerstone of the Axis Powers alliance, the anti-Soviet economic blockade and war coalition, also constituted a declaration of war on the Soviet Union.