In an archipelago of safe houses here, part of a 21st-century Underground Railroad, I met groups of people who live every moment with sickening fear.

These are North Koreans who have escaped to the “free world” — China — and are now at constant risk of being captured by Chinese police. The Chinese government, in a disgraceful breach of its obligations under the 1951 Refugees Convention, hands these escapees back to North Korea, where they face beatings and imprisonment, occasionally even execution