Melding the Hanukkah holiday and foreign affairs, Prime Minister Benjamin Netanyahu solemnly vowed to serve as a “light unto the nations” and act against Iran’s nuclear program should diplomacy fail Thursday night.

Speaking at the Western Wall for a Hanukkah candle-lighting ceremony, Netanyahu compared Iran’s nuclear program to a darkness that would be forced out by Israel, referencing a popular children’s song for the holiday.

“We came to drive out the darkness, and the largest darkness that threatens the world today is a nuclear Iran,” he said. “We are bound to do all we can to prevent this darkness. If possible we will do this diplomatically, if not we will act as ‘a light unto the nations’.”

Jerusalem has denounced a deal signed Sunday between Iran and six world powers that eases sanctions in return for limits on uranium enrichment and a more intrusive inspections regime.

Earlier Thursday, Yaakov Amidror, the former head of the Israeli National Security Council took to the pages of The New York Times to rail against the nuclear deal between world powers and Iran, calling the accord a diplomatic failure that missed the mark in diverting Tehran’s nuclear weapons program.

“The agreement represents a failure, not a triumph, of diplomacy,” Amidror wrote.

Netanyahu has been castigated at home and abroad for taking a harsh stand against the US and Europe for signing the deal, with critics claiming he is deepening Israel’s isolation while strengthening the Iranian regime.

The prime minister, however, said he had “not given in to delusions” that Iran would pull back its nuclear program, comparing the nuclear deal to a failed diplomatic initiative meant to stymie North Korea’s nuclear program.

“I believe in speaking the truth, and standing for important principles in order to ensure peace in the world and our security, and of course our peace,” he said. “We will continue to act in this spirit.”

The prime minister added that Jerusalem was in talks with the US and P5+1 to ensure that a final deal “brings a final result of the dismantling of Iran’s ability for a military nuclear program.”

Peres: Iranians and Israelis not enemies

Speaking on a state visit to Mexico City, President Shimon Peres struck a more conciliatory tone, saying Israel preferred diplomacy and that Iran and Israel were not enemies.

He called on Tehran to stop sponsoring terror, end its nuclear program and halt development of long-range missiles.

“There are countries that try to take advantage of this transition [in the Middle East] and attempt to overpower other countries and stop their march to the new age,” Peres said. “They do it by building nuclear threats, centers of terror, tongues of hatred. Iran has signed an interim agreement with the P5+1. Success or failure of the deal will be judged by results, not by words.

“As far as Israel is concerned, we do not consider the Iranian people our enemies,” he stressed. “We do not share a border. We do share a common history. It demonstrates that we can be friendly. There is an opportunity to solve this issue diplomatically. It is in your hands. Reject terrorism. Stop the nuclear program. Stop the development of long-range missiles,” he continued.

“Israel like the rest of the international community prefers a diplomatic solution. But the international community will not tolerate a nuclear Iran. No one threatens Iran. When Iran will cease to threaten others, it will liberate itself from the burden which it has brought upon itself. I truly hope that this deal will free the Iranian people from being a source of menace and will turn it into a contributing nation for peace. Only time will tell,” he said, sounding rather more optimistic than Netanyahu over the deal.

“Israel extends its hand in peace to all its neighbors. But we have learned from bitter experience to beware of tyrants. Tyranny has no message for the future. It offers dark nights instead of enlightened days.   The real promise of progress lies in the employment of science and technology by a society which seeks justice and peace,” said Peres.