It fell to the last speaker at the United Nations yesterday, Israeli Prime Minister Benjamin Netanyahu, to warn the U.N. General Assembly of Iran’s new charm offensive.

Sanctions, not negotiations, are the way to deal with Iran’s nuclear program, Netanyahu said. His final warning was stern and categorical: “Israel will not allow Iran to get nuclear weapons,” he said. “If Israel is forced to stand alone, Israel will stand alone.”

The Obama Administration and the international community should heed Netanyahu’s warnings. Netanyahu reminded the General Assembly that newly elected Iranian President Hassan Rouhani’s message and image of friendliness is only skin deep. He compared Rouhani to his fire-breathing predecessor Mahmoud Ahmadinejad.

“The only difference between them is this: Ahmadinejad was a wolf in wolf’s clothing. Rouhani is a wolf in sheep’s clothing, a wolf who thinks he can pull the wool over the eyes of the international community,” Netanyahu said.

Netanyahu’s words were echoed by Israeli President Shimon Peres, who said on Monday during a visit to The Hague that Iran should be judged “by deeds” rather than a mere charm offensive.

An example of the international eagerness to give Rouhani the benefit of the doubt was the CNN news story that Rouhani had denounced the Holocaust, a scoop delivered by CNN’s Christiane Amanpour.

CNN reported that Rouhani had reversed Ahmedinejad’s denial of the Holocaust and denounced the slaughter of the 6 million Jews by the Nazis during World War II, but Rouhani did not, in fact, do this. As noted by the Iranian Fars News Agency, CNN mistranslated and misinterpreted his statements. This is what Rouhani said verbatim, according to Fars:

I have said before that I am not a historian and historians should specify, state and explain the aspects of historical events, but generally we fully condemn any kind of crime committed against humanity throughout the history, including the crime committed by the Nazis both against the Jews and non-Jews, the same way that if today any crime is committed against any nation or any religion or any people or any belief, we condemn that crime and genocide. Therefore, what the Nazis did is condemned, (but) the aspects that you talk about, clarification of these aspects is a duty of the historians and researchers, I am not a history scholar.

It was a clever non-answer to Amanpour’s question about the Holocaust.

The idea that Rouhani would do a 180-turn on any issue related to Israel and the Jewish Holocaust is highly unlikely, especially when considering his track record.

Rouhani led Iran’s Supreme National Security Council from 1989 through 2003. This was the time when Iranian-backed terrorists gunned down opposition leaders in a Berlin restaurant, murdered 85 people at the Jewish community center in Buenos Aires, and killed 19 American soldiers by blowing up the Khobar Towers in Saudi Arabia.

Rouhani was Iran’s chief nuclear negotiator from 2003 to 2005, the mastermind of a strategy that in Netanyahu’s words “enabled Iran to advance its nuclear weapons program behind a smokescreen of diplomatic engagement and very soothing rhetoric.”

Even as U.S. Secretary of State John Kerry makes plans for nuclear talks with Iran later this month, and President Obama basks in his phone chat last week with his Iranian counterpart, Rouhani’s—and Iran’s—true colors must be understood.