10 Times Star Trek Went Woke
2. Leave Your Bigotry In Your Quarters
Balance Of Terror introduces the Romulans, it is the final appearance of Janice Rand until The Motion Picture, and it is the episode in which Kirk utters the immortal line:
Leave any bigotry in your quarters. There's no room for it on the bridge.
While the episode is often considered for its Romulan legacy, it is the character of Stiles that is the true focus. Stiles, a Starfleet officer, is openly racist and hostile toward Spock, who as a Vulcan looks identical to the (contemporary) Romulans. This evolves as Stiles refuses Spock's help in the phaser room, only for an accident to almost claim his life and threaten the Enterprise. Spock intervenes, saving Stiles and the ship in the process.
Kirk's command to Stiles is clear, though it also highlights how even in the future, humans will judge on looks and prejudice alone. Balance Of Terror was born out of a particularly paranoid time. The HUAC hearings and McCarthy-inspired mistrust of one's neighbours, especially in Hollywood, feed into the depiction of Stiles. Kirk is unable to stop this mistrust in his officer and is only able to order him not to act on it.
This is perhaps one of the most prescient messages that Star Trek ever delivered, with the quote still finding supporters and detractors today.