What Has a Map of the Khazar Empire to Do with "Palestine"?

{Reposted from the author's blog}

If you visit this site, you'll observe a list of maps of Palestine.

And at the bottom you can see one of the Khazarian Empire:

Background:

In 1976, Arthur Koestler...in The Thirteenth Tribe, argued that most Ashkenazi Jews are descended from the Khazars, a Central Asian people who ruled a large kingdom on the Black Sea and apparently converted to Judaism in the 8th century. This hypothesis has been taken up more recently by Shlomo Sand in a book called The Invention of the Jewish People. Koestler, one of the oddest and most extraordinary public intellectuals of the 20th century, wanted to weaken anti-Semitism by demonstrating that many Jews weren’t Semites at all. Sand, a self-avowed post-Zionist who teaches at Tel Aviv University, is apparently driven by the desire to prove that Ashkenazi Israelis are interlopers in the Middle East.

Al Jazeera and many other Arabs believe it as it would justify their claim of European Jews being a foreign entity as it is for Russian nationalists, a:

pretext for arguing that Jewish intrigues and dominance were to be found from the very beginning of Russian history. In this context the term “Khazars” became popular as a euphemism for the so-called “Jewish occupation regime.”