Karmi does not say the world is in the grip of a Jewish doctrine, but in the grip of segregationism. Therein lies your problem.
Yes he does, actually.
I'm amazed at your horrid reading comprehension.
The first source that comes to one’s mind is the Jewish doctrine that divides humanity into those who are Chosen and those who are Gentiles. This doctrine seems to have imprisoned the world in its grip.
Do you need an English teacher to explain to you why the subject of the first sentence "Jewish Doctrine" is "this doctrine" in the next?