Yes, it is true that North Korea has been actively developing and testing nuclear arms for the last decade, since most of their facilities and tests are easily traceable.
The convention was held during a year of violence, political turbulence, and civil unrest, particularly riots in more than 100 cities following the assassination of Martin Luther King Jr. on April 4. The convention also followed the assassination of Robert F. Kennedy on June 5. Both Kennedy and Senator Eugene McCarthy of Minnesota had been running for the Democratic nomination at the time.
