No Vivien, no Waste Land.

It's been said before, but it's said again in this review of col. 4 of the letters:

In a rare newspaper interview in 1994, Valerie Eliot said that her husband wrote The Waste Land because Vivian made him suffer. “We owe the poem to her, no question: he wouldn’t have written it if she hadn’t given him such hell.” And in oblique confirmation of this claim, in a letter included here, discussing The Waste Land with E M Forster on August 10 1929, Eliot says: “You exaggerate the importance of the War… The Waste Land might have been just the same without the War.” It is perhaps not surprising that during the last near-decade of Eliot’s life when his second marriage gave him unprecedented happiness that his creative output diminished accordingly.

http://www.telegraph.co.uk/culture/books/booknews/9808196/The-Letters-of-TS-Eliot-Volume-4-1928-1929-ed-by-Valerie-Eliot-and-JohnHaffenden-review.html