As written in Richard Condon’s hilariously overheated novel, Eleanor Iselin is Lady Macbeth armed with Gertrude’s incestuous sex drive. This ain’t hamartia — it’s strength. And it’s only an eleventh-hour, deus-ex-machina moment of clarity that compels Shaw to murder his mother and step-father. As presented by screenwriter George Axelrod, Eleanor’s sexual affection for Shaw is acknowledged but never consummated. It works better this way. You sense that Eleanor has literally overplayed her hand (Shaw’s murderous instincts are activated by the Queen of Diamonds), but you doubt the young man’s resolve — and this doubt is wholly predicated on Lansbury’s performance.
Lansbury’s Eleanor is a gloriously evil reptile. She holds in her hands not just the fate of her cuckolded husband and addled son, but the global balance of power. She has successfully, through years of coordination with the Soviets, orchestrated a palace coup. Once her drunken blowhard of a spouse assumes power, she’ll call the shots and destroy her enemies. For her, the United States is not enough, and this is the kicker — she did not know Shaw had been brainwashed.
It is, as Roger Ebert noted in his Great Movies essay, a reckless, seemingly illogical move on Russia’s part. But of course these Kremlin baddies underestimated Eleanor.