The last leader of the former Soviet Union and the man who introduced “glasnost,” or openness, to Soviet politics passed away on Tuesday at the age of 91.

Mikhail Gorbachev’s policies led to an eventual end to the decades-long Cold War and the easing of nuclear tensions with the west.

Memorial University political scientist Luke Ashworth says Gorbachev was a breath of fresh air when he took over after the death of Konstantin Chernenko in 1985.

“He changed so much, and tried to reform the Soviet Union after a long period of stagnation,” says Ashworth, but ultimately failed to “do the one thing that he was trying to do which was to rejuvenate, resuscitate, and save the Soviet Union. He ended up being, of course, one of the architects of the collapse of the USSR.”

Ashworth says Gorbachev was a complex political figure and while he will be fondly remembered in the west, he will be less fondly remembered in countries like Lithuania where he sent in troops to prevent it from breaking off from the Soviet Union.