What led to the feeling of isolation as the crew arrived in pyongyang

North Korean people took all the electronics so they would not have access to the outside world led to the feeling of isolation as the crew arrived in Pyongyang.

The dictator in that country believed that if the people of Pyongyang have free access to information, they've might be exposed to various information that discredits him as a leader.

Fully isolating the people from outside information would basically allow him the power to totally control the perception of the people.