Ariel Sharon, the former Israeli prime minister who died last night after an eight-year coma, is an historical enigma.

The most controversial figure in modern Zionism, the admired and brutal military commander, the uncompromising opponent of reconciliation with the Palestinians, he proved upon becoming the prime minister to be the one Israeli politician willing to make the type of concession that could have propelled the peace process forward after years of stagnation.

Sharon came to favor a unilateral withdrawal of all Israeli troops and settlers from the Gaza strip. That's like a Republican presidential candidate insisting that his party's platform support the right to choose an abortion.

How did a man so proud, so hawkish, move to a position that startled even the Palestinians?

The regnant American leadership paradigm might be when Richard Nixon brokered an opening with China, but the better comparison, I think, is in Ronald Reagan's 1986 proposal, made in a moment of private candor, to cut the United States arsenal of strategic nuclear weapons to zero if Mikhail Gorbachev would do the same, a gesture so audacious that his advisers were forced to deny he had ever even considered such a thing. (The summit in question ended in a stalemate over the Strategic Defense Initiative).

Reagan's admirers never like to admit that he evolved, as a man does, and instead tend to stick to the the nostrum that circumstances changed to fit his beliefs, or that his beliefs influenced circumstances.

Of Ariel Sharon, says Jeffrey Goldberg:

What changed was not his heart, not his life's aim, but his understanding of reality. In his heart, he understood Israel's enemies to be implacable. His objective was unaltered: to defend the existence of the Jewish state by any means necessary. For many years, he believed that the existence of the Jewish state was dependent on the occupation of Gaza. But he then came to realize that the "occupation" of Gaza was undermining Israel's democracy, international standing and security. And so he left. He left Gaza for the same reason he invaded Lebanon: He thought it would make Israel safer.

This, to me, is evidence of the man's having changed, much to his credit. I'm not sure why the c-word is an insult. The most imaginative and far-reaching initiatives of leaders tend to result from the unique perspective their job brings, and their own willingness to "think in time," a quality defined by Richard Neustadt and Ernest May. The past is prologue, of course, but progress happens when leaders see the old paths and deliberately change course. One's understanding of reality is one's point of view; when leaders come to see something new, it generally is because they've concluded that the old ways, what they learned or thought they knew, didn't fit the situation. Something else made more sense. And leaders, presidents and prime ministers are particularly suited to look at the totality of something. (John F. Kennedy knew immediately that the Jupiter missiles in Turkey would have to be sacrificed in order to accommodate the Soviet Union; the Cuban Missile Crisis took days to solve not because the solution wasn't at hand but because everyone around him had to buy into it in order for it work.)

Good leaders think in time. They think above normal politics and their own resentments. Ronald Reagan applied the lessons he learned as president well, and he chose to change the way the United States responded to nuclear disarmament proposals, albeit with an even temper and a flexibility that allowed for politics and the process to play itself out. Reagan never changed his beliefs about the evilness of communism, or the potential dangers posted by Russia, or the wisdom of a strong conventional military deterrent.

Whatever else Sharon was, he proved himself capable of being a statesman.