Key Reasons Beyond Collapse of Soviet Union

The Soviet Union seemed formidable in the mid-1980s, so why did it collapse in just a few years? Due to the weak economy and internal ethnic tensions? Yes, and no.
1. Oil prices and economic inefficiency
“The date of the USSR's collapse is well known. It's not the day of the Belovezha Accords, nor the August coup [of 1991]. It was Sept. 13, 1985 when Saudi Arabia's Minister of Oil, [Ahmed] Yamani, declared that Saudi Arabia was quitting the agreement on oil production restraint, and started to boost its share in the oil market. After this, Saudi Arabia increased oil production by 5.5 fold, and oil prices dropped by 6.1 fold,” wrote Egor Gaidar, the architect of radical economic reforms in post-Soviet Russia in the 1990s.