President Wilson's statement that "we didn't do these things because they are easy but because they are hard" is paraphrasing a speech by John F. Kennedy on September 12, 1962 where he said "We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard."
The cassette player used by Lee Jung-Gil is a Califone CAS1500 dating from around 1984. These were made in China mainly for use in American schools and libraries. It is not unrealistic that a North Korean would have a Chinese-made device.
The pistol used by Lee Jung-Gil is a Type 68, a North Korean copy of a Soviet TT-30.
The van that Jimmy is in has the numbers 1701 on it. This is a nod to Star Trek and the registry number of the U.S.S. Enterprise, NCC-1701. Creator and Executive Producer Ronald D. Moore previously wrote and produced for numerous Star Trek productions in the 1990s.