<P> Gross domestic product (GDP) increased for three Allies (Britain, Italy, and U.S.), but decreased in France and Russia, in neutral Netherlands, and in the three main Central Powers . The shrinkage in GDP in Austria, Russia, France, and the Ottoman Empire reached 30 to 40% . In Austria, for example, most pigs were slaughtered, so at war's end there was no meat . </P> <P> The Western Front quickly stabilized, with almost no movement of more than a few hundred yards . The greatest single expenditure on both sides was for artillery shells, the chief weapon in the war . Since the front was highly stable, both sides built elaborate railway networks that brought supplies within a mile or two of the front lines, with horse - drawn wagons used for the final deliveries . In the ten - month battle at Verdun, the French and Germans fired some 10 million shells in all, weighing 1.4 million tons of steel . </P> <P> Economic warfare against Germany worked--the British blockade was effective . The German counter-blockade with U-Boats was defeated by the convoy system and massive American ship building . Britain paid the war costs of most of its Allies until it ran out of money, then the US took over, funding those Allies and Britain as well . </P> <P> The economy (in terms of GDP) grew about 7% from 1914 to 1918 despite the absence of so many men in the services; by contrast the German economy shrank 27% . The War saw a decline of civilian consumption, with a major reallocation to munitions . The government share of GDP soared from 8% in 1913 to 38% in 1918 (compared to 50% in 1943). </P>

British trade decreased after world war 1 because