The V-2 rocket was one of several innovative long-range weapons developed by the Germans after the failure of the Luftwaffe to strike a decisive blow against Britain. It was a revolutionary weapon—the world's first operational SRBM—that had been developed in a secret programme begun in 1936. The German leadership hoped that a barrage of rockets unleashed against London would force Britain out of the war. Although Adolf Hitler was at first ambivalent, he eventually became an enthusiastic supporter of the V-2 programme as Allied air forces carried out increasingly devastating attacks on German cities.