In the summer of 1989, Tim Walz faced a difficult choice.

A newly minted college graduate from small-town Nebraska, he had just turned down a stable, 9-to-5 job offer and moved across the world to teach at a local high school in China.

He had made it as far as Hong Kong, just across the Chinese border, when People¡¯s Liberation Army tanks rolled into Tiananmen Square to crush pro-democracy protests.