"If I Forget..."

We found two Biblical quotations among the chapter headings of Poul Anderson's After Doomsday. There is at least one more in the text. Carl Donnan thinks:

"If I forget thee, O Jerusalem!"
-CHAPTER SEVEN, p. 77.

But he thinks it of the whole Earth! He has just been remembering invaders:

"Romans in Greece, Saxons in Britain, English in Ireland and India, Spaniards in Mexico -" (ibid.)

Before that, having just been captured by the Kandemirians, he remembered almost nostalgically the two previous times he had been a prisoner:

"At their worst, those jails had stood on a green and peopled Earth." (p. 73)

If I forget...