The end of the verse “which does not know You” is not clear as to what is the reference. In general all the nations of the world do not know HaShem. The verse seems to imply only this nation does not know but others do know Him.
However, it can be explained that the clause is not a reference to those nations, but is a sub-clause explaining why His anger should be poured on these nations, since they do not know HaShem. And this was evidenced by the continuation of the verses which explain that they consumed Yaakov and destroyed his habitations.
Similarly, one can explain the Medrash at the end of Parshas BeShalach. When Amalek came to attach the Jews in the desert, Moshe commanded Yehoshua to war with Amalek. Why did Moshe specifically pick Yehoshua? Moshe said the descendant of Yosef (Yehoshua was from the tribe of Efraim) for whom it is said “HaShem I fear”, should command against Amalek upon whom it is said does not fear Hashem.
This Medrash needs explanation. Why did the Medrash need a verse that Yosef said about himself that he fears HaShem, when we know the righteousness of Yosef without the verse? And among all the sons of Yaakov no one else was known to fear HaShem? Further, what is special about Amalek that they are referred to as not fearing HaShem? We are aware even among the Jews only a select few are known as truly fearing HaShem. Even Avrohom was not referred to with this title of “fearer of HaShem” until after the Akeida.
The explanation is that Yosef specifically exemplified the concept that one could exist within the nations of the world and yet achieve a position of “fearer of HaShem.” Thus, where ever they live, all (Jew or not) have the ability to achieve this level.
And Amalek specifically came to deny that this concept and to promulgate that the level of “fearer of HaShem” can not exist in the “real” world. Therefore, Amalek assumed the title of “did not fear HaShem.” Therefore, the descendent of Yosef was specifically chosen to lead the refutation of Amalek.
