"What happened on the night of August 7 is beyond comprehension," Gorbachev said in an article The Guardian published on Wednesday. "The Georgian military attacked the South Ossetian capital of Tskhinvali with multiple rocket launchers designed to devastate large areas."
"Russia had to respond. To accuse it of aggression against 'small, defenseless Georgia' is not just hypocritical but shows a lack of humanity," he said in the article.
"Nevertheless, it was still possible to find a political solution. Clearly, the only way to solve the South Ossetian problem on that basis is through peaceful means. The Georgian leadership flouted this key principle," Gorbachev, a Nobel Peace Prize laureate, said.
Gorbachev told the paper that the Georgian authorities could only undertake the offensive "with the perceived support" of a much more powerful force - an apparent reference to the United States, which has trained Georgian troops and backed the country's bid to join NATO.
Now that the military assault has been routed, Gorbachev said, "the Georgian government and its supporters should rethink their position."
Gorbachev said some Western nations' positions prevented the UN Security Council from acting effectively at the start of the conflict. He also said that by declaring the Caucasus region that is thousands of miles from the American continent a sphere of its "national interest," the U.S. made a serious blunder.
"Of course, peace in the Caucasus is in everyone's interest. But it is simply common sense to recognize that Russia is rooted there by common geography and centuries of history. Russia is not seeking territorial expansion, but it has legitimate interests in this region," The Guardian reported him as saying.
Gorbachev said the international community should in the long term seek to create a sub-regional security system to make the possibility of crises impossible, which requires cooperation with regional countries and fair and unbiased stances of nations outside the region.
"A lesson from recent events is that geopolitical games are dangerous anywhere, not just in the Caucasus," he said.
"Already, thousands of people have died, tens of thousands have been turned into refugees, and towns and villages lie in ruins. Nothing can justify this loss of life and destruction. It is a warning to all," Gorbachev said.
Georgia and Russia agreed on Tuesday to a modified version of a French-brokered interim peace plan, which requires an immediate ceasefire and the pullback of forces to their previous positions. The European Union approved the plan on Wednesday.
Georgia's territorial integrity and the return of refugees would be the focus of the next stage of talks, French President Nicolas Sarkozy earlier said.
However, Russia's military said Tuesday that Georgia is failing to completely abide by the ceasefire and sniper attacks are continuing, and Russian peacekeepers have to respond to provocative attacks.
Georgia also reported the continued movement of Russian troops inside its territory. Russia denied the reports.