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.