Hezekiah, the king of Judah, faced a similar threat. The kings of Assyria had already defeated the nations surrounding Judah, and Sennacherib, the current Assyrian king, was determined to add Judah to the list of tributary nations. Like Ahmadinejad, he also started with threats of total annihilation.
The general of the Assyrian host called aloud to the king’s servants which were on the walls of Jerusalem: “Thus says the great king, the king of Assyria, In what do you place your trust? If you say, we trust in the Lord our God, do you think that we have come against you without the Lord? For the Lord said to me, Go against this land and destroy it. Let not Hezekiah deceive you, for he will not be able to deliver you out of the hand of the king of Assyria.
“Neither let Hezekiah make you trust in the Lord your God, saying that the Lord will surely deliver this city out of the hand of the king of Assyria. For have any of the gods of the nations delivered them out of the hand of the king of Assyria?” And with many other such threats and blasphemies, the general of the Assyrian host mocked Hezekiah and the Lord God of Israel.
Hezekiah then prayed, “O Lord God of Israel, You alone are God, who made heaven and earth. And now see the words of Sennacherib, with which he has reproached the living God. It is true, O Lord, the kings of Assyria have destroyed the nations, and have cast their gods into the fire, for they were no gods, but the work of men’s hands, therefore they have destroyed them. Now I beseech You, save us out of his hand, that all the earth may know that You alone are God.”
That very night, the angel of the Lord went out, and smote in the camp of the Assyrian host every man of valor, every captain of the host, one hundred and eighty-five thousand warriors. When Sennacherib arose in the morning, all his camp was filled with dead bodies. Thus he returned to his own land, with shame on his face (710 BC).
It just so happened that Sennacherib was murdered through a conspiracy after he had returned home. At any rate, he was removed from power, and his threats against Israel came to nothing. You can read the history of Hezekiah and Sennacherib in 2 Kings 18-19.
Today I saw in the news, that hardliners are turning on Ahmadinejad for watching women dancers, something prohibited by Iran's Islamic law. I have no idea what will happen with Iran and Ahmadinead, except that I don't believe God will allow another Holocaust, even if Israel were delivered miraculously from Iran's threats as Judah had been so many years before. I would not be surprised if Israel was restored to the Lord instead.