What was similar about warfare in the early 1800s and early 1900s ? Please explain.

European nations began a massive military buildup. These nations formed a complicated network of alliances to protect themselves from opposing armed forces. ... The use of trench warfare was used in the early 1900s and not in the 1800s.

Explanation:

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.