"O nations – sing the praises of His people, for He will avenge the blood of His servants." (Devarim 32:43) What significance is there to the song of the other nations, that the Song of Ha'azinu concludes with it?

We see from Moshe's prayer, as well, that there is great significance to what the nations might say: "Then the nations that heard of Your fame will say, 'Because Hashem lacked the ability to bring this people to the Land that He had sworn to give them'..." (Bamidbar 14:15-16) Yehoshua also said, "The Canaanite and all the inhabitants of the of the land will hear ... What will You do for Your Great Name?" (7:9)

G-d Himself agreed with this argument, and says in Parshat Ha'azinu: "I had said, 'I will scatter them, I will cause their memory to cease from man.' Were it not for the fact that the anger of the enemy was pent up ... lest they say, 'Our hand was raised in triumph, and it was not Hashem who accomplished all this!'" (Devarim 26-27)

What is the great concern about what the nations say?

The Ramban explains in our Parsha that we are the only nation in the world that recognizes the Creator and know that there is a purpose to the Creation, If we are lost from the world, there will be no one left who will know Him, and the whole purpose of the Creation will be lost. The troubles with which the nations afflict Israel are all out of their hatred of G-d. Therefore, what stands in the balance is not Am Yisrael, but rather the Master of the World and His revelation in the world.

This is what Yeshaya said: "You are My witnesses and I am G-d." (Yeshaya 43:10) Chazal comment on this: "If you are My witnesses – I am G-d; if not, as it were – I am not G-d." This is what Moshe and Yehoshua prayed about, that without Israel, "What will You do for Your great Name?" R. Yehuda Halevi writes on the pasuk, " I will go down with you to Egypt and I will also bring you back up" (Bereishit 46:4), that here is the greatest of all promises, that G-d's name will be called over Israel. This means that his honor be spread throughout the world only through Israel, and so long that Israel are downtrodden, His glory will be hidden.

Therefore, when the nations are able to point a finger at Israel, to ridicule and ask, "Where is their G-d?" this is a great desecration of G-d's Name, so this is what they all prayed: "Why should the nations say..." This is the purpose of Israel, that the name of G-d should be commonplace in the mouths of all the nations, until the goal is achieved in the future: "Many peoples will go and say, 'Come let us go up to the Mountain of Hashem' ... For from Zion will the Torah come forth and the word of Hashem from Yerushalayim." (Yeshaya 2:3) Everyone will acknowledge the supremacy of Israel and they will recognize their longstanding mistake.

This is the main point of the prayers of the High Holy days: "Give your fear, Hashem, our G-d, over all the nations ... and all the creatures will bow done before You ... Thus, give honor to Your nation." Through, "your fear over the nations," there will be honor for Israel, as all will recognize Him, "and all that have breath in their nose will say – Hashem, the G-d of Israel, is King." Similarly, in the prayers of the festivals we say: "Reveal the honor of your kingdom over us, and appear and be raised above us before all lives."

The conclusion of this process will be when, with G-d's help, the nations will recognize this, not out of fear, but out of rational understanding and fear of Heaven, and then all the nations will sing.