Some early strategists/visionaries after World War I imagined that airpower alone would suffice to bring nations to their knees. The Bombing of Guernica was an early trial that revealed both capabilities and limitations. But yet another maxim, "no war was ever won solely by airpower" was challenged by the NATO victory in Kosovo. Airpower has been used to conduct lightning strategic strikes, to complement land offensives, to instill fear and lower morale similarly to a fleet in being, and to create broad-based destruction behind enemy lines. With airpower, supplies can be transported by cargo planes, providing a decisive edge in mobility.