Belgium was not a belligerent in the Franco–Prussian War (1870–1871) but was heavily influenced by the social and political effects of the conflict. An invasion of Belgian territory by either side was widely feared in 1870 and the Belgian Army was mobilised. The inadequacies which this revealed in Belgium's military and defensive preparations led to calls to reform the system of conscription and for a programme of fortification-building which would greatly influence the early phases of World War I.