In 1995, David Glantz stated that for the first time, blitzkrieg was defeated in summer and the opposing Soviet forces were able to mount a successful counter-offensive. The Battle of Kursk ended with two Soviet counter-offensives and the revival of deep operations. In the summer of 1944, the Red Army destroyed Army Group Centre in Operation Bagration, using combined-arms tactics for armour, infantry and air power in a coordinated strategic assault, known as deep operations, which led to an advance of in six weeks.