What does the irony in these excerpts from “In Another Country” by Ernest Hemingway convey?

The war is ruthless and took away the things most important to the identity and happiness of both men.

Explanation:

Your question isn't complete as you didn't provide the excerpt where the question came from. I searched online and got the excerpt which has been added in the comments section.

Irony refers to the expression of one's meaning through the use of a language

or words which signifies the opposite. The irony in the excerpts convey that the war is ruthless and took away the things most important to the identity and happiness of both men.

he sent troops to protect the students as they entered the school.

you will need these

an outline of all three paragraphsan identification of the historical era that you are writing aboutan explanation of the term mass productiona description of two ways new technology affected industrya conclusion that shows how new technologies allowed industrialization to grow