The Shell Crisis of 1915 was a shortage of artillery shells on the front lines of World War I that led to a political crisis in Britain. Military historian Hew Strachan argues that strategic plans caused an over-reliance on shrapnel to attack infantry in the open, which caused a shortage of high-explosive shells in most major armies. At the start of the war there was a revolution in doctrine: instead of the idea that artillery was a useful support for infantry attacks, the new doctrine held that heavy guns alone would control the battlefield. Because of the stable lines on the Western Front, it was easy to build rail lines that delivered all the shells the factories could produce. The "shell scandal" emerged in 1915 because the high rate of fire over a long period was not anticipated and the stock of shells became depleted.