The British military—the leading U.S. military ally and Europe’s biggest defense spender—has only around 150 deployable tanks and perhaps a dozen serviceable long-range artillery pieces. So bare was the cupboard that last year the British military considered sourcing multiple rocket launchers from museums to upgrade and donate to Ukraine, an idea that was dropped. France, the next biggest spender, has fewer than 90 heavy artillery pieces, equivalent to what Russia loses roughly every month on the Ukraine battlefield. Denmark has no heavy artillery, submarines or air-defense systems. Germany’s army has enough ammunition for two days of battle.