Lee Myung Bak

Back then, they called him the Bulldozer. As a driven young executive for Hyundai Construction in the 1970s and '80s, Lee Myung Bak helped build much of postwar South Korea, working with others to transform a bombed-out agrarian economy into one of the most dynamic industrialized nations in the world. He saw his brother and sister killed during the Korean War, and he hauled trash to pay for his university tuition, yet he rose to become CEO by age 35. Today, Lee is likely to be South Korea's next President.

But the rapid development that remade the nation and lifted millions like Lee out of poverty left lasting scars on South Korea. Nowhere are those wounds deeper than in the capital of Seoul, an unlovely city of 10 million that was dusty, polluted and congested by the time Lee ran for mayor in 2002.

For decades, those who lived in Seoul had simply sighed and survived their unlivable city. This was the deal, after all, for Asia's economic tigers — prosperity came at a cost of worsening pollution. A clean environment was considered an unaffordable, Western extravagance. But Lee had the courage — and the political smarts — to realize that for South Korea's newly affluent middle class, the deal needed renegotiating. "When the Korean economy was just trying to get back on its feet after the war, having parks was a luxury," the 65-year-old Lee told TIME last year. "But now we try to achieve a balance between function and the environment, and we try to put the environment first."

So the Bulldozer went green — and in dramatic fashion. He told the city's people that he would tear out the jam-packed elevated highway that ran through the heart of Seoul and restore the buried Cheonggyecheon stream — a foul urban waterway that Lee himself had helped pave over in the 1960s. His opponents insisted that the plan would cause traffic chaos and cost billions, but the voters elected Lee. Three years later, Cheonggyecheon was reborn, an environmentally friendly civic jewel that has changed the face of Seoul. More quietly, Lee also revamped the city's transportation system, adding clean rapid-transit buses. But his lasting accomplishment was in changing the Asian political dynamic, showing that environmentalism can go hand in hand with development.