Radak: It is destruction, like "b'Vala Rasha Tzadik Mimenu" (Chabakuk 1:13).

Malbim: Before Mashi'ach comes, the nations will be divided into two camps. (a) They have Emunah and do not serve idolatry, just they do not recognize the true creed. The false Emunah puts a veil over their faces, and blocks them from seeing the light of truth. It would be easy for them to recognize the true Emunah, since they already believe in many fundamentals, e.g. reward and punishment, Hashgachah... They are called Amim - a higher level than Goyim. Hashem will swallow and remove the veil over their faces, i.e. the false Emunah, and automatically they will see clear light and the true creed by themselves. (b) Refer to 25:7:3:3.

Rashi: It is the cover on the nations. This is like "va'Yalet Panav" (Melachim I, 19:13), "Hine Hi Lutah va'Simlah" (Shmuel I, 21:10).

Radak #1: The first ha'Lot is a noun; the second is a verb, like "veha'Masechah ha'Nesuchah."

Radak #2: The second ha'Lot is an adjective.

Radak citing his father: This hints to a nation that covers their faces.

Rashi: It is an expression of Nesichus and authority.

Radak: The verse repeats the matter in different words. The covering and covertness in which the nations hid until that day, that they all had Shalom and authority, Hashem will destroy the cover. They will be exposed and prepared for the evil that will come upon them. They will have no shelter from it. It says "Pnei ha'Lot", for until that day they were covered, as if they do not have visible faces - "Shachta Va'ado", "Asher Darko Nistarah" (Iyov 1:10, 3:23).

Malbim: Some Goyim have no Emunah; they worship idols like ancient Goyim, like people of China and Japan. Hashem will remove the idolatry, which is a mask over them, to be their gods and stray after them.