In my review of episode 8, I said:

Tet was like the chain reaction phase of an A-Bomb - it's all over in 30 nanoseconds; but it takes another whole second for the enormous energy released to begin to become manifest macroscopically.

That energy should have ended the war in 1968. Instead, we got Nixon, who prolonged it for another seven years. Nixon was what nuclear weapons people call "a tamper".