I'm sure iain
has a point from the genetic
point of view - I myself, though distinctly European
in appearance, have epicanthic folds
, probably the legacy of a long ago raped and pillaged ancestress
that chanced to stray across the path of the Mongols
. But that doesn't make me part Mongol.
I have ancestors from Poland, Russia, Rumania, Germany, Afganistan, Buchara, Azerbaijan, the Ukraine, Georgia and Iran among others. However, all of them being Jewish, I myself am all Jewish. Doesn't make senes? That's Jewish geography for you.
Let's look at the French for a moment. They're a nation which coalesced from various dukedoms, principalities and cities to eventually come under the rule of a single dynasty. Its borders have always been highly contested, and populations drifted across them more or less freely - to and from Germany, Switzerland, Belgium, Spain and, in modern times, North Africa. Still, you wouldn't question the nationality of people who are a genetic mix of all these European and North African peoples, they are all indisputabley French. Very much the same case can be made for the Swiss, the English (who are even a wilder mix through successive invasions), the Russians, the Chinese...
What differentiates all these people from the Jews is that they have a more or less definite physical location on which to peg their nationality. Jews haven't had that luxury for about two thousand years. If you manage to ignore the fact that people who claim they are Jewish by nationality do not come from one nationalist state (Israeli Jews tend to refer to themselves as Israelis, strangely enough, I know I do), you'll see that intermarriages and migrations aside, they still have a fair case.