I detest lies.
-
Mikhail Gorbachev (1989)

The glasnost policy re-wrote Soviet history. Stalin, Brezhnev, and Cherenko were exposed as oppressive murderers, leaving only Lenin as sacrosanct, and history books became useless. Before, only information about their atrocities was only released if it benefited the person currently in power and this initiative brought some of the whole truth to the Soviet people and the world. Although the initiative did permit discussion and reflection on the past, more radical voices were still silenced in the early years of the policy.

By 1989, glasnost was out of control and it was used to criticize Gorbachev. Ideas like the abolition of the Community Party's leading role in the government, multi-party democracy, and the failure of perestroika were widely discussed in the liberal media. The change came after the Chernobyl disaster on April 26, 1986 and the 48 hours of silence that followed. After those two days, the honesty of the government and information provided were unlike anything that had happened in the past. Environmental concerns were a topic that the liberal media embraced and as people became more angry about their government's incompetence the truth came out piece by piece.

Glasnost left the country in a mess, but for the first time in Soviet history the truth was available and the government was being pushed to explain its actions.

Sources:
http://www.historyorb.com/russia/glasnost.shtml
http://www.search.eb.com/ebi/article?eu=335470&query=glasnost

Considering the political and historical context in which the term glasnost I feel it deserves more than a simple translation to english. So for your edification and wonderment I would like to now provide a complex translation, with a little bit of etymology thrown in to spice things up.

Glasnost': this word is made up of two separate meaningful parts: glasn- and ost'. Glasn- is the word stem, most commonly seen in the adjective glasnii, meaning public. The suffix -ost' is a commonly used suffix to change an adjective into a noun with the meaning of "being in the state of" the adjective. For example the word molodost', meaning "youth" (or the state of being young), is a common word formed from the adjective molodoi, "young". One of my hoziaka's favorite toasts is za molodost', or "to youth."

So glasnost', from glasnii, means the state of being public, which we translate as "openness" because "publicness" sounds a bit odd in English.