Good choice!
However, I'm not sure if it specifically relates to foreign relations and diplomacy.
And don't you wish there were a second edition covering more modern "intellectuals"?
You are correct - it doesn't exactly relate to foreign affairs, but its transcendent. People like Marx, who Johnson scathingly covered, ended up driving virtually all of the foreign policy of the 20th century.
And I completely agree, it would be nice to have a second edition that covers our modern "intellectuals". Interesting how we use that term to describe people that are basically ignorant and closed minded. Another one of life's ironies.