The Shell Crisis of 1915 was a shortage of artillery shells on the front lines in the First World War that led to a political crisis in the United Kingdom. The military historian Hew Strachan wrote that military strategy led an over-reliance on shrapnel to attack infantry in the open, which was negated by the resort to trench warfare, for which high-explosive shells were better suited. 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 railway 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. The inciting incident was the disastrous Battle of Aubers, which reportedly had been stymied by a lack of shells.