writes "A US military reconessaince plane was reportedly forced to perform an emergency landing during a major military exercise near the North Korean border in March. As revealed by the South Korean defense ministry, a strong signal transmitted from the north disrupted GPS in the area surrounding the position of the RC-7B aircraft. Without information about their position, the pilots were forced to abort their mission and return to South Korea.
This leaves the question whether the US military would be able to perform operations in North Korea given how fragile their equipment seems to be.
http://www.google.com/hostednews/afp/article/ALeqM5hVgo7A86GctR-2Yqp7oGEDEqX9PA?docId=CNG.d4f84b5e07fc041894b51b397f3a85be.a1"Link to Original Source