It's been discussed since 1985, with implementation attempts in 1986 before the Chernobyl disaster, but only accepted as the official policy (Glasnost-Perestroi

It's been discussed since 1985, with implementation attempts in 1986 before the Chernobyl disaster, but only accepted as the official policy (Glasnost-Perestroika-Acceleration) in 1987. I still have a Uborevich-Borovsky's satirical comic book published in 1986 with Glasnost taking probably one third of it.