[5] His battalion was sent to France in late 1917, where they underwent intensive training for trench warfare from French and British instructors,[6] and were transferred to the frontline in spring 1918, by which point Krulewitch held the rank of sergeant.
[7]Krulewitch's unit later participated in the Meuse-Argonne Offensive and by the night of 10 November 1918, they had crossed the Meuse river and made an attack on the opposite bank.
[8] However, the marines had suffered heavy losses and when Krulewitch collected the survivors of his unit together, he found that he only had 11 men remaining out of a company of over 200.
[4] During World War II, Krulewitch held the rank of lieutenant colonel and served with the 4th Marine Division in the Asiatic-Pacific Theater.
In March 1945, during the Battle of Iwo Jima, Krulewitch commanded the 4th Provisional Battalion, which was responsible for attacking bypassed Japanese positions.