World War I Begins By World War I began in August 1914. In contrast to the United States, which had fewer than a dozen military airplanes at that time, Germany, France and England had 180, 136 and 48 aircraft, respectively. These nations soon discovered the immense value of aerial reconnaissance to their armies and a race began to build up their flying forces. Within a short time, each realized the importance of denying this aerial reconnaissance to the enemy; thus aerial combat was born. During the first several years of the war, great strides were made in airplane design and performance, in the development of gunnery and bombing equipment, and in aerial combat tactics and techniques. The airplane became a true weapon of destruction over the battlefield of Europe. Click here to return to the Early Years Gallery. Find Out More Other Resources World War I Centenary .