By 1914, armies had adopted machine guns without understanding their full impact. One gun could match the firepower of 30 riflemen, turning cavalry charges and infantry advances into calculated ...

At 10:59 a.m. on Nov. 11, 1918, a German machine gun crew fired a burst of rounds at approaching Americans. One bullet struck 23-year-old Pvt. Henry Gunther in the left temple. He died instantly.

A Russian strategist has argued that infantry weapons such as mortars and machine guns are obsolete. He said he believed drones would replace them, making infantry units smaller and lighter. Light ...