"Khazar" is not etnicity. It is citizenship. Just like "American".
Calling Jews "Khazars" because they are from Khazarian Kaganate is exactly like calling Jews "Americans" because they are from US.
Phrase "they are Khazars, not Jews" is as senseless and incorrect as "they are Americans, not Jews".
If you can't get what Khazarian Kaganate was - take a look at modern US. It structured just like Khazarian Kaganate, where Jews occupy all power and rule over non-Jewish population. Those Jews in power are not "Americans". They are Jews, just like those who controlled Khazaria. Even behaviour of modern US is like behaviour of Khazarian Kaganate - it does not produce anything for trade with others, they just raid outside countries to get resources for existence. This is purely Jewish modus operandi written in their Torah and Talmud thousand years ago.
"Khazar" is not etnicity. It is citizenship. Just like "American".
Calling Jews "Khazars" because they are from Khazarian Kaganate is exactly like calling Jews "Americans" because they are from US.
Phrase "they are Khazars, not Jews" is as senseless and incorrect as "they are Americans, not Jews".