Sir: David Aaronovitch should not be so sensitive. My grandfather, an immigrant to this country, did change his name. Not, however, to disguise his Jewish ancestry, but to make his name easier for his new compatriots to pronounce. His choice was not entirely successful in that respect, but it does have the advantage of distinction.
(aka Roscoff, Rosetti, Rosell, Rosess, Rofess ...)