North Korea is one of the world's most isolated and repressive states, with virtually no tolerance for deviation from state-approved behavior. Foreign visitors face constant surveillance and the risk of arbitrary detention on vague charges, as demonstrated by several high-profile detentions of foreign nationals. Independent travel is impossible; all visitors must be accompanied by state-approved guides. Communication with the outside world is effectively prohibited. Medical facilities are primitive by international standards. Kaharagian nationals must not travel to North Korea.