A Dangerous Game; Garry Kasparov had it all, until he gave up chess for the rough-and-tumble world of Russian politics.

Byline: Garry Kasparov (Kasparov is the chairman of the United Civic Front in Russia and the author of "How Life Imitates Chess.")

On March 10, 2005, I played my last game of competitive chess after three decades as a professional. The announcement of my retirement was a bit theatrical, delivered without warning at the end of a Spanish tournament in Linares I'd just won for the ninth time. In one day I went from the top of the chess world to a politician in Russia's struggling pro-democracy movement.

There was no dramatic moment of judgment, no single incident that told me the time was right. Nor was it a spontaneous move. Every decision we make is the product of our entire life up to that point--all our knowledge, experience, intuition and calculation. I've spent considerable time since my retirement writing a book on exactly this topic: the decision-making process. The result, "How Life Imitates Chess," represents a careful analysis of my own development as a decision maker, and my leap from chess to politics is detailed. The book itself was one of the things I wanted to dedicate myself to after retiring; as a professional chess player I'd never had the time.

My feelings about chess itself were the least significant element in my decision to quit. Chess had been my life for many years (I started playing at 6), and it will always be important to me. Far more important, however, was the need to make a difference. I had achieved everything that could be achieved in the chess world. Forty-one years old when I retired, I could have continued fighting to keep my No. 1 spot for another five years. But I increasingly felt my role in the chess world was no longer an essential one. I was ready for new challenges.

At the same time, my country was descending into crisis. The authoritarian nature of President Vladimir Putin's regime had become increasingly obvious, and the government was threatening to become a full-blown dictatorship. The kleptocratic police state established by Putin and his gang had revived many of the Soviet ways and means: control of the media, a puppet judiciary, stage-managed elections. The glimmer of democracy that existed during the messy Yeltsin years was being entirely extinguished. The simple ...