In so many ways, the world we know today would not be the same without Mikhail Gorbachev, the last leader of the former Soviet Union, who died at the age of 91 on Tuesday, writes David A. Andelman.

From 1985 to 1991, Mikhail Gorbachev was the architect of glasnost and perestroika. ... Gorbachev sat at the head of the table like a shell-shocked Caesar, Raisa and their daughter by his side.

Mikhail Gorbachev – the last leader of the former Soviet Union from 1985 until 1991 – has died at the age of 91. Gorbachev died after a long illness, Russian state news agencies reported.

Then-Soviet President Mikhail Gorbachev addresses a group of 150 business executives in San Francisco, California, on June 5, 1990. Gorbachev died Tuesday at the age of 91. David Longstreath/AP ...

Mikhail Gorbachev – the last leader of the former Soviet Union from 1985 until 1991 – has died at the age of 91.