The 1839 Treaty of London recognised Belgium as an independent and neutral state.
Until 1911, Belgian strategic analysis anticipated that if war came, the Germans would attack France across the Franco-German border and trap the French armies against the Belgian frontier, as they had done in 1870.
British and French guarantees of Belgian independence were made before 1914 but the possibility of landings in Antwerp was floated by the British military attaché in 1906 and 1911, which led the Belgians to suspect that the British had come to see Belgian neutrality as a matter of British diplomatic and military advantage, rather than as an end in itself.
The Agadir Crisis (1911) left the Belgian government in little doubt as to the risk of a European war and an invasion of Belgium by Germany.

In September 1911, a government meeting concluded that Belgium must be prepared to resist a German invasion, to avoid accusations of collusion by the British and French governments.
Britain, France and the Netherlands were also to continue to be treated as potential enemies.
In 1913 and 1914, the Germans made inquires to the Belgian military attaché in Berlin, about the passage of German military forces through Belgium.
If invaded, Belgium would need foreign help but would not treat foreign powers as allies or form objectives beyond the maintenance of Belgian independence.
Neutrality forced the Belgian government into a strategy of military independence, based on a rearmament programme begun in 1909, which was expected to be complete in 1926.
The Belgian plan was to have three army corps, to reduce the numerical advantage of the German armies over the French, intended to deter a German invasion.

Conscription was introduced in 1909 but with a reduction in the term of service to fifteen months; the Agadir Crisis made the government continue its preparations but until 1913, the size of the army was not fixed as a proportion of the population.
The annual conscription of 13,300 recruits was increased to 33,000 to accumulate the trained manpower for a field army of 180,000 men.
Older men would continue to serve as garrison troops and by 1926 340,000 men would be available.
Implementation of the new scheme had disrupted the old one but had not become effective by 1914.
During the crisis over the assassination of Archduke Franz Ferdinand of Austria, regiments were divided and eight conscription classes were incorporated into the army to provide 117,000 men for the field army and 200,000 fortress troops.
The Belgian army planned all-round defence, rather than concentrating the army against a particular threat.
Belgian defences were to be based on a National Redoubt at Antwerp, with the field army massed in the centre of the country 60 km (37 mi) from the border, ready to manoeuvre to delay an invasion, while the frontiers were protected by the fortified regions of Liège and Namur.
The German invasion of Belgium on 4 August 1914, in violation of Article VII of the Treaty of London was the casus belli, the reason given by the British government, for declaring war on Germany.
The 1839 Treaty of London recognised Belgium as an independent and neutral state. Until 1911, Belgian strategic analysis anticipated that if war came, the Germans would attack France across the Franco-German border and trap the French armies against the Belgian frontier, as they had done in 1870. British and French guarantees of Belgian independence were made before 1914 but the possibility of landings in Antwerp was floated by the British military attaché in 1906 and 1911, which led the Belgians to suspect that the British had come to see Belgian neutrality as a matter of British diplomatic and military advantage, rather than as an end in itself. The Agadir Crisis (1911) left the Belgian government in little doubt as to the risk of a European war and an invasion of Belgium by Germany.
In September 1911, a government meeting concluded that Belgium must be prepared to resist a German invasion, to avoid accusations of collusion by the British and French governments. Britain, France and the Netherlands were also to continue to be treated as potential enemies. In 1913 and 1914, the Germans made inquires to the Belgian military attaché in Berlin, about the passage of German military forces through Belgium. If invaded, Belgium would need foreign help but would not treat foreign powers as allies or form objectives beyond the maintenance of Belgian independence. Neutrality forced the Belgian government into a strategy of military independence, based on a rearmament programme begun in 1909, which was expected to be complete in 1926. The Belgian plan was to have three army corps, to reduce the numerical advantage of the German armies over the French, intended to deter a German invasion.
Conscription was introduced in 1909 but with a reduction in the term of service to fifteen months; the Agadir Crisis made the government continue its preparations but until 1913, the size of the army was not fixed as a proportion of the population. The annual conscription of 13,300 recruits was increased to 33,000 to accumulate the trained manpower for a field army of 180,000 men. Older men would continue to serve as garrison troops and by 1926 340,000 men would be available. Implementation of the new scheme had disrupted the old one but had not become effective by 1914. During the crisis over the assassination of Archduke Franz Ferdinand of Austria, regiments were divided and eight conscription classes were incorporated into the army to provide 117,000 men for the field army and 200,000 fortress troops. The Belgian army planned all-round defence, rather than concentrating the army against a particular threat. Belgian defences were to be based on a National Redoubt at Antwerp, with the field army massed in the centre of the country 60 km (37 mi) from the border, ready to manoeuvre to delay an invasion, while the frontiers were protected by the fortified regions of Liège and Namur. The German invasion of Belgium on 4 August 1914, in violation of Article VII of the Treaty of London was the casus belli, the reason given by the British government, for declaring war on Germany.
German invasion of Belgium