Something that causes and event to occur is known as a(n)

Catalyst

Explanation:

The definition of Catalyst is: someone or something that causes something to happen or change. Another way this word is described is as person or thing that precipitates an event, in other words, that makes an event occur.

This word is used a lot in chemistry to describe a substance that speeds up a chemical reaction.

no options provided, here,but the answer to this question is often: a historian cites a japanese newspaper article published a year after the end of world war ii in order to draw conclusions about the effect of the war on the japanese economy.

clearly from the answer, the historian alludes to historical sources,and records to aid in analyzing and drawing conclusion on the effect of the war on the economy of japan.

declare war, appoint military officers, sign treaties, make alliances