The episode title refers to a common economic model that gives an example of how a country can apportion limited resources on either defence (guns) or production of domestic goods (butter) or a combination of both but to increase one you need to reduce the other.
When the President (Martin Sheen) calls Josh (Bradley Whitford) Maxine, he refers to Hallmark Cards character Maxine, known for demanding that people agree with her.
In the airport scene, Donna walks past an extra holding a sign that reads "B. D'elia". The episode was directed by Bill D'elia.
In this episode, it is learned that Will Bailey went to Eton College. Eton is located in Eton, Berkshire, England. This tracks with his backstory that his father was former Supreme Commander NATO Allied Forces Europe.