This represents an abrupt reversal of a decades-long decline. During the second world war the Allies devoted half of theirgdp
Although Russia and Ukraine have deployed enormous conscripted armies, Western countries that are rearming remain mostly committed to the idea that quality beats quantity. Better, the logic goes, to have a smaller army equipped with state-of-the-art artillery, tanks, planes and equipment than a bigger one with rusty kit.
Ultimately what matters in war is not the absolute level of a country’s defence capabilities, but its strength relative to that of enemies. If everyone is upgrading capabilities, then the result will be an arms race in which, for every innovation, there must be a countervailing rise in spending. The technological change that has enabled Russia to launch Iranian drones stuffed with explosives at civilians has raised the cost of defending Ukraine, for example.