We’ve spent quite a bit of time examining the parallels between the Americans and the Soviets during the Cold War, and “The Oath” does a good job of continuing in that vein. It explores the similarities and differences between Martha (Alison Wright) and Clark/Philip’s (Matthew Rhys) friendship, and Stan’s (Noah Emmerich) relationship with Nina (Annet Mahendru), and shocks me with some of the outcomes.