Lee, Rand B. "Knight of Shallows"
Divergence: 1982 CE
What if: Margaret Thatcher was assassinated and the Falklands crisis went nuclear.
Summary: Barely allohistorical tale in which a man hunts a murderous version of himself through different Key Wests.
Published: In Amazing Stories, July 1983; The Year's Best Science Fiction, First Annual Collection (ed. Gardner Dozois), Bluejay 1984 (0312944837, 0312944829); and The 1984 Annual World's Best SF (eds. Donald A. Wollheim and Arthur W. Saha), DAW 1984.