The French desire to revenge the harsh treatment suffered from the Germans after the Franco-Prussian War of 1870-71 especially the loss of Alsace-Lorraine rich in minerals and the heavy indemnity, imposed by the Germans influenced the French to extend the war to Germans, Cameroon.
Britain wanted to revenge the Germans annexation Coup in July 1884, which led to the loss of Cameroon to Germany
The British desire to defeat the Germans in Cameroon, and make territorial gains in order to readjust or tidy up her Nigerian frontiers.
The French desire to expend her French Equatorial Africa Empire by gaining territories in Cameroon, influenced them to extend the war to Cameroon, to achieve their dream of creating a large empire of unbroken territories from Algiers to Brazzaville. Furthermore, the French desire to regain part of French Equatorial Africa given to the Germans in 1911, to introduce he recognize her claims over Morocco after the Agadir crisis of 1911, influenced them to extend the war to Cameroon to regain the territory.
The desire of the Belgians to revenge the German violation of her Neutrally in 1914 by their invasion of France through the Franco-Belgium borders, provoked the Belgians to intervene with their colonial forces against the Germans in Cameroon, when the war broke out in August 1914.
The strategy of the allied power to accelerate the defeat of the German by extending the war to the German protectorates including Cameroon in order to force the Germans fight the war on many fronts and weaken their military power.
The strategy of the allied powers to prevent reinforcement from the German colonies against them influenced them to extend the war to Cameroon in August 1914.
The desire of the Allied Powers to capture Cameroon and Increase their Naval Power in the Atlantic Coast of West Africa forced them to extend the war to Cameroon in 1914. They wanted to capture the German transmission station and the German Naval base in Douala that was a threat to allied shipping in the Atlantic Coast of West Africa.
The desire of the British to advertise her Naval Power and Naval superiority over the Germans. This was because prior to the War German was a challenger to the British Naval Power in Europe.
The desire of Britain and France to increase their bargaining power in post war settlement, after the defeat of the Germans, influenced them to extend the war to capture the Germans protectorate including Cameroon.