CHANGBAI, China – Like the smell of coal that wafts from across the narrow Yalu River, suspicion and hostility toward outsiders hang thick in the air of this quiet border town, which peers into a dilapidated North Korean city.

Arriving after nightfall, our first interaction with a local besides our hotel’s receptionist makes it clear that foreigners aren’t welcome in the urban center of Changbai Korean Autonomous County, from which North Korea’s Hyesan is separated by as little as 30 meters (a little less than 100 feet) of water. When we enter a fruit and vegetable shop to ask about the origin of the produce, the owner immediately accuses our Chinese interpreter of being a prostitute. Back out on the dimly lit street, an elderly man follows our party for several minutes before apparently losing interest and resuming what seems like an aimless stroll.