Explain how propaganda was used to mobilize populations (both in the home countries and the colonies) for the purpose of waging war

During World War One, propaganda was employed on a global scale.

Explanation:

Unlike previous wars, this was the first total war in which whole nations and not just professional armies were locked in mortal combat. This and subsequent modern wars required propaganda to mobilise hatred against the enemy; to convince the population of the justness of the cause; to enlist the active support and cooperation of neutral countries; and to strengthen the support of allies.

Furthermore, when the government needed to recruit lots of soldiers and wanted people to support them.  Posters were printed that made the army look exciting. Other posters told men it was their duty to join, that they would feel proud if they did and guilty or embarrassed if they didn't join.

frederick william of brandenburg-prussia trained his son, frederick, to be a hardy soldier. but frederick disliked rifle shooting and horseback riding. unlike his father, he was interested in french literature. he enjoyed poetry and music and, like some others of the enlightenment, he scoffed at religion. his father thought him soft, frivolous and unmindful of his duties. and when frederick refused to put his signature on a right to succession, for a few moments his father strangled him.

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."