Kyiv’s European allies are snapping up its military know-how as they seek to build up their own defenses.

Warfare transitioned from open battlefields to urban environments. Compact carbines with shorter barrels replaced full-length rifles for maneuverability. Combat now occurs predominantly after dark.

The U.S. launched a powerful attack on Iranian targets using advanced weaponry such as Tomahawk missiles, F-18 and F-35 fighter jets, and innovative one-way attack drones. The action signifies a shift ...