Brokaw, with the aid of producers Brian Brown and Joe Gesue, spent two years shooting "Their Finest Hour" across London, Dover, Coventry, Portsmouth, Bladon and Cambridge, where they interviewed victims of Germany's sustained bombing attacks. The producers also unearthed some haunting color footage of Europe during the war that hasn't been seen in years. 

Several of the interviews in the film were also conducted down in Winston Churchill's London war rooms, which have been preserved to this day. The site is a monument to a time when, as Brokaw puts it, England was all that was left between liberty and tyranny.

Why is it important to revisit this now? "Coming here for the Olympics during a time of great economic uncertainty and anxiety, it is important to remember the lessons of sacrifice and unity in that much more dangerous era," says Brokaw. People who have spent their time tweeting and whining about NBC's tape delayed coverage as if it were an affront to humanity should take note.