The last few weeks have underlined that Prime Minister Benjamin Netanyahu can be rhetorically and practically effective when dealing with external threats, as he faced up to Syria’s vows to attack Israel in case of a US strike on its territory. What’s less clear is how effectively he grapples with ostensible tolerance from long-time foes, as in the charm offensive being mounted by Iran’s sophisticated new president, Hasan Rouhani.

Netanyahu was calm and level-headed in handling the Syria crisis. In the days after US President Barack Obama threatened to punish the regime of Bashar Assad for its August 21 chemical-weapons attack, and before a Russia-brokered deal made such a strike exceedingly unlikely, the prime minister was responsibility personified. Despite repeated threats from Tehran and Damascus that Israel would “come under fire” if the US intervened, Netanyahu instructed his ministers to keep quiet and let Washington handle the situation, while he himself issued well-balanced statements that did not provoke Assad but, rather, deterred him from attacking by making it plain that Israel would not hesitate to respond forcefully.

Iran’s new campaign to win the hearts and minds of the West, however, requires a different kind of reaction. But although Netanyahu and his ministers anticipated the change of tone from Tehran, they do not appear to have formulated an effective response; instead, they are stubbornly repeating the same messages they issued when the easy-to-demonize Mahmoud Ahmadinejad was the public face of the Islamist regime.

Over the last few days, Rouhani has sent message after message signaling the Islamic Republic’s eagerness to engage with the West over its nuclear program. Rouhani purports to have abandoned Ahmadinejad’s warmongering, and has allowed it be reported that it might be ready to compromise on the nuclear program – even though, publicly, the president reiterates that uranium enrichment is Iran’s right and that he has no intention of halting what he risibly insists is a purely peaceful program.

Screenshot from an interview Iranian President Hasan Rouhani gave to NBC News Wednesday September 18, 2013, his first to a US outlet since his election.

Screenshot from an interview Iranian President Hasan Rouhani gave to NBC News Wednesday, September 18, 2013, his first to a US outlet since his election

Iran has never sought — and will never seek — a nuclear weapon, Rouhani promised last week on an American television network, nor does it “seek war with any country.” These words are music to American ears. If Netanyahu considers them to be utterly disingenuous, and he plainly does, simply saying “I don’t believe him,” or words to that effect, isn’t sufficient anymore. Sweet-talking, reasonable-sounding, berobed Rouhani is a lot tougher to discredit than the Holocaust-denying, gay-bashing, unkempt Ahmadinejad.

The West — whose desire to avoid further military misadventure was starkly illustrated by its response to Assad’s chemical-weapons outrage — is unsurprisingly inclined to test Rouhani’s sincerity. While assuring Jerusalem that they will not be fooled by Tehran’s sweet talk, the Americans are receptive to the idea of a possible détente. The White House has not ruled out a possible Obama-Rouhani meeting on the sidelines of the United Nations General Assembly this week in New York, something that would have been unthinkable just a few weeks ago. French President Francois Hollande is set to meet with Rouhani at the UN, as is British Foreign Secretary William Hague, even though Britain does not have diplomatic relations with Iran.

Israel’s hugely skeptical response to Rouhani’s slick PR may be entirely justified. But showing the new friendly face of Tehran to be disingenuous requires more than a recycling of the same-old bleak sound bites. Cartoon bombs — as unveiled by Netanyahu at last year’s UN General Assembly — aren’t going to work anymore. This year’s show is going to have to be more serious and nuanced.

“The Iranians are continuing to spin in the media so that the centrifuges continue spinning. The real test lies in the Iranian regime’s actions, not words,” Netanyahu said in a statement Thursday night, immediately after Rouhani’s peace-loving interview. The prime minister reiterated, as he has done dozens of times in the past few months, the four conditions the international community needs to demand from the Iranians: halting all uranium enrichment, removing already enriched material, shutting down the Fordo nuclear facility in Qom, and discontinuing the plutonium track. Until these four criteria are fulfilled, said Netanyahu, the world needs to “intensify the pressure,” not ease it.

Mahmoud Ahmadinejad speaking at the United Nations on Monday. (photo credit: AP/Seth Wenig)

Mahmoud Ahmadinejad speaking at the United Nations in 2012. (photo credit: AP/Seth Wenig)

Likewise, Intelligence and Strategic Affairs Minister Yuval Steinitz said in an interview published over the weekend that “Rouhani has launched a charm offensive on the West, but he plans to charm his way to a nuclear weapon. While he sends letters to Obama and wishes the Jews a happy New Year, the centrifuges continue to spin. Not only has the [nuclear] project not stopped, it is galloping forward.”

Israel has all the reasons in the world to be wary. The Iranians are savvy tacticians and Rouhani is clearly willing to go a long way rhetorically to persuade the West to ease sanctions that are biting into the economy, while relentlessly inching toward the bomb.

Indeed, Steinitz predicted Rouhani’s reported willingness to suspend uranium enrichment weeks ago. “He will come to the West, just like he did in 2003 [when Rouhani was Iran’s chief nuclear negotiator], and say: ‘Let’s make an interim deal. I’ll make a few concessions here, you will make some concessions there,” Steinitz told The Times of Israel in August. The Iranians might even offer unilateral gestures, such as, for example, halting uranium enrichment at the Qom facility for three or four months, Steinitz said. “But after that, [Rouhani] will request reciprocity. He will say, ‘Now show me that you are easing the sanctions so that I can prove to the Iranian people that this approach pays.’ He will come with a concept of confidence-building measures. He will say there is no trust, and trust is built step by step.”

The skeptical Israeli argument is sound; the concern is that it is insufficient. Repeating the same mantra may produce diminishing returns when the world’s perception of Iran is changing. Tehran is remaking its image, rapidly, from a saber-rattling, Holocaust-denying rogue state, bent on wiping Israel off the map, to a peace-loving, truce-brokering, would-be haven of modernity. Israeli leaders are not alone in doubting there’s been a genuine change of heart, but many in the West, most notably President Barack Obama, are disinclined to dismiss it out of hand.

“Disparaging knee-jerk reactions” such as the Prime Minister’s Office’s “obligatory too-clever-by-half pun about ‘spinning’ the media in order to keep the centrifuges ‘spinning,’ wouldn’t have cut it any more, even in the best of times,” Chemi Shalev wrote from the US in Sunday’s Haaretz. Israel needs to be aware that “Americans are in a peace-in-our-time kind of mood,” in which they would like to believe that Iran can really be a constructive partner in solving the Middle East’s many problems, he noted.

At junctures like this, dreaming of an era of reduced conflict, even usually responsible leaders can allow themselves to become forgetful — to put aside, for a moment, Iran’s appalling history of fostering terrorism; to gloss over its brutal repression of internal dissent; and to ignore the fact that much of its purportedly peaceful nuclear program was constructed in secret, in breach of its international obligations, and is plainly focused on attaining a weapons capability.

And even to forget that Rouhani is a creature of the regime, not an opponent — a politician carefully selected as one of only six presidential candidates approved by Supreme Leader Ali Khamenei, a practiced diplomatic manipulator with the nous to have temporarily frozen the Iranian nuclear program when it was feared that the US would be coming for Iran after Iraq in 2003, only to revive it again when the danger had passed.

When Rouhani speaks a different language to his predecessor, and the West seems ready to listen, Israel’s disinclination to adapt risks isolation — rather than empathy — for Jerusalem

Yes, regimes, even the most demonic, can change. But Netanyahu’s and Israel’s interest lies in reminding the rest of the West of the necessary barometers to measure that change — encouraging the maintenance of pressure so that Tehran is prodded in the right direction, pushing an incremental approach, where only measurable change matters — not fine rhetoric.

Thus far, Netanyahu’s relentless warnings about Iran’s approaching nuclear weapons capability, and his not-so-subtle threats to use military force as a last resort to prevent a nuclear Iran, have done much to alert the world to the dangers. Even Western officials who oppose the prime minister’s Iran policy admit that.

But when Rouhani speaks a different language to his predecessor, and the West seems ready to listen, Israel’s disinclination to adapt risks isolation — rather than empathy — for Jerusalem. It hardly helps, of course, that much of the West already regards Israel as being as much of an aggressor state as is Iran.

“Respect him, but suspect him,” a common Hebrew expression advises, yet embracing ostensibly friendly gestures by enemy entities was never Netanyahu’s strong suit. That is also why his answer was rather cold when, earlier this year, the Arab League considered for the first time the possibility of mutually agreed land swaps in the framework of its Arab-Israeli peace Initiative, making a significant step toward Jerusalem’s position.

At least Netanyahu said, at the time, that Israel agrees “to discuss any initiative that is proposed and that is not a dictate.” Iran’s current charm offensive, by contrast, is being rejected outright… at least by the prime minister. Interestingly, as so often, it has been President Shimon Peres who has been more nuanced: “The sanctions are doing their job and are influencing the leadership in Iran,” Peres said Friday. “I hope we are hearing a new voice coming from [Tehran],” he said.

Obama would like to believe that the Syrian crisis is being solved through diplomacy, and that the Iranian threat might just be averted in the same way. Israel’s doubts are more than reasonable. But right now Rouhani is singing a new tune, and Netanyahu risks sounding like a broken record, repeating a song people would much rather not listen to anymore.