The problem with punishing Pyongyang by stopping North Koreans from traveling to the United States is that there are very few — almost none — making the trip.

The new executive order suspends “immigrant and nonimmigrant” travel from North Korea to the United States. But people cannot immigrate from North Korea to the United States to begin with.

“They should have checked if there is North Korean immigration before they banned it,” said John Delury, an associate professor at Seoul’s Yonsei University. “Why are you banning something that doesn’t exist?”