A few hours ago CNN and every other major news outlet reported that North Korea has declared invalid the 1953 armistice that ended the Korean War. Part of the CNN article included a short video about the history of conflict on the Korean peninsula. That video is embedded below.
For a longer explanation of the Korean War, Keith Hughes has a sixteen minute overview for high school students.
This video gives us just the facts about the Korean War in three minutes.
The Guardian offers a short, interactive slideshow about North Korea's weapons testing. The slideshow is two years old, but the graphics on how the tests are conducted are still useful.
The BBC's country profile on North Korea is a resource that students can use to get a quick overview of history of North Korea in a timeline format. Teachers who have students that have read Lois Lowry's The Giver may want to ask students for their thoughts on the media section of the BBC's profile of North Korea.