In very simple terms:
The Archduke of Austria Franz Ferdinand was assassinated by a Serbian which caused Austria-Hungary to make a list of demands to end Serbia's influence in Bosnia. The Serbians rejected the demands and Austria-Hungary declared war on Serbia.
Unwilling to lose their own influence in the Balkans Russia mobilized for war with Austria-Hungary. Germany, Austria-Hungary's ally declared war on Russia.
France who were going through government instability saw the situation as a chance to use war to enact reforms and retake the Alsace-Lorraine province lost to Germany in the Franco-Prussian war and so France mobilized against Germany.
Great Britain Entered the war when Germany refused to guarantee Belgium's neutrality and sovereignty.
The Moroccan crisis and the Bosnian crisis
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I really don't know
A lot of factors but mainly nationalism, the versaille treaty and the great depression.
Militarism, Alliances, Imperialism, and Nationalism.
because world war 1
they guns
The Moroccan crisis and the Bosnian crisis
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because there cool
I really don't know
Post-War labor disputes
A lot of factors but mainly nationalism, the versaille treaty and the great depression.
I really don't know
Militarism, Alliances, Imperialism, and Nationalism.
Imperialism, Militarism, and Entangled Alliances
They did not lead to war; they were part of the war. They were, however, factors in the United States' decision to enter the war.