During the 1960s, both the U.S. and Soviet militaries began designing new supersonic strategic bombers. The American Rockwell B-1 Lancer ended up fulfilling a conventional bombing role, but the superficially similar design pursued by the Soviets was a bit more grand. They created the Tupolev Tu-160, nicknamed the White Swan: the world's largest and heaviest bomber, with the most powerful jet engines ever mounted on an aircraft. Unlike its American counterpart, it was intended for stand-off missile launching, including of course nuclear missiles.
The size and impressive capabilities of this behemoth came with a hefty price tag. Though the Soviet military ordered 100 White Swans, the expense and difficulty of manufacturing meant that fewer than 40 were actually built. Finally entering production in 1984, the model never saw action during the Cold War. Only in 2015 did it first enter combat as part of Russian bombing attacks in Syria. Nevertheless, Russia's military has continued to modernize and upgrade its fleet, and has even planned to relaunch production of White Swans.