Eliot said that a merchant came to him at the bank in which he worked with currants in his pockets and a proposal much like the one depicted in the poem.
Donald J. Childs proposed the Eliot would have been reminded of the Gallipoli campaign where his friend Jean Verdenal was killed when the Near East Conference convened in London early in 1921 and made news. Here the Turks and Greeks argued over who, in the aftermath of the war, should have control of the Dardanelles and of the port of Smyrna (now Izmir).
In the same essay, Childs discussed the significance of Stetson in The Waste Land. See the Stetson commentary.
Childs, Donald J., "Stetson in The Waste Land," Essays in Criticism, (April 1988) pp. 131-148
(Say, when did the Near East get moved to the Middle East anyway?)