W​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​hy was the Soviet Union beginning to crumble economical​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​y in the 1970s and 1980s? Why was Glasnost necessary​‌‍‍‍‌‍‍‍‌‍‍‍‌‌‌‌‌‌‍‍​?