Originally, Jessica Yu was set to direct 'We Killed Yamamoto,' however Thomas Schlamme, anticipating a late delivery of the script before production and thus less preparation, offered to take her place instead, and reschedule her directing for the next season. Yu accepted and Schlamme ended up having less than two days of prep before shooting.
Leo (John Spencer) claims that the U.S. spent millions of dollars developing a pen that would write in space while the Russians just used a pencil, but this account is inaccurate. Development of the space pen was independently funded by inventor Paul Fisher, who sold them to NASA at $6 apiece. The Russians began buying the same pen a year later. (Prior to adopting the space pen both countries had used pencils in space, but this practice was abandoned due to their flammability and the risk of tips breaking off and floating around in microgravity. Graphite conducts electricity and could short-circuit electronics.)
Fitzwallace (John Amos) claims that if Bonhoeffer had been successful, the Germans would have built a statue of an assassin. However, pacifist theologian Dietrich Bonhoeffer had nothing to do with the July 20 attempt on Hitler's life (although he was falsely accused of this by the Nazis). The key conspirator and would-be assassin was Claus Schenk Graf von Stauffenberg.
Bartlet (Martin Sheen) says that marriage incentives involve the government getting into the yenta business, a Yiddish word for a busybody/gossip. Leo (John Spencer) wonders that Bartlet didn't grow up in the Catskills - an area formerly famous as a Jewish holiday resort.
Fitzwallace (John Amos) uses the example of the Battle of Agincourt to discuss how well enemies were treated if they surrendered. However, Agincourt is an example of the opposite. After the first and second attacks by the French, they had too many prisoners. Fearing the prisoners would overtake them, Henry ordered them slaughtered. The code of chivalry does not permit such action, so Henry had his archers aim at the knights and forced them to kill the prisoners.
In this episode Leo (John Spencer) says that the Russian solution for writing in zero gravity is the use of a pencil. This is an urban myth, It would actually be dangerous, if the tip were to break off and float around freely.
The trivia item below may give away important plot points.
The title foreshadows upcoming events. In 1943, after having decoded Japanese admiral Isoroku Yamamoto's travel itinerary for an inspection tour, US forces dispatched a fighter group, which subsequently intercepted and shot down his plane.