Project 667BDR, also known as the Dolphin-class submarine, is a Soviet-era military project that focused on developing a series of nuclear-powered submarines. These submarines were designed for strategic deterrence and to enhance the naval capabilities of the Soviet Navy during the Cold War. The project resulted in the construction of several submarines, which were equipped with advanced technology for their time, including ballistic missile systems. The 667BDR submarines played a crucial role in maintaining the balance of power at sea and were part of the broader Soviet military strategy.