Prime Minister Benjamin Netanyahu came to New York with one goal in mind: pouring cold water on Hassan Rouhani charm offensive and discrediting the Iranian president’s ostensibly moderate positions in the nuclear standoff with the West.

During his speech Tuesday at the United Nations, Netanyahu spared no effort to expose how the Iranian leader’s recent statements — including from the same podium as week earlier — contradict his true positions and intentions, telling the world that Rouhani is “a wolf in sheep’s clothing” who “executes political dissidents by the hundreds” and thinks “he can have his yellowcake and eat it too.” The nuclear Iran sought by the “savage” regime that Rouhani represents, warned Netanyahu, would be like “another 50 North Koreas.”

Netanyahu mentioned Rouhani by name more than two dozen times, quoting articles, statements and positions attributed to the newly elected president dating back to his tenure as Iran’s national security adviser in the 1990s. (A bit of a low blow, some analysts opined, since Netanyahu knows only too well how politicians’ positions can change over time.)

Rouhani wooed the West with his benevolent UN speech last Tuesday, and followed it with a media blitz during which he kept on espousing benign and peace-loving positions, vowing not to seek nuclear war with any nation, and even condemning the Nazis’ crimes against the Jews and others.

Netanyahu came to the US to rain on Rouhani’s parade. He relishes being a party-pooper, taking the air out of Rouhani’s PR balloon. And Tuesday’s speech was just the beginning.

In a highly unusual step, the prime minister is devoting much of two days in New York to giving interviews to as many American news outlets as possible. Originally scheduled to return to Israel on Wednesday, he extended his stay by a full day to make sure most every interested American journalist gets the chance to learn about Rouhani’s real orientation — or at least Netanyahu’s depiction of it.

Netanyahu wants to have the last word, but the timing of the “charm defensive” is somewhat unfortunate, with Rouhani long since gone, his gracious presentations resonating all last week and through the weekend, and with the American public now preoccupied with the government shutdown and Obamacare.

Nonetheless, the prime minister is eagerly embarking on his marathon sessions of interviews, repeating the soundbites about Rouhani’s alleged duplicity, knowing how important public opinion is when it comes to decisions of war and peace in the Middle East — not least because of the recent Syrian precedent.

Last month, US President Barack Obama issued a military threat against the Bashar Assad regime, following the alleged chemical weapons attack on August 21 that killed more than 1,000 civilians. But after British Prime Minister David Cameron lost a debate in Parliament on military intervention, and polls showed strong American opposition to military action, Obama backed away, said he would first consult Congress, and ultimately endorsed a Russian-led initiative to seek a negotiation solution that would strip Assad of his chemical weapons.

Netanyahu well understands American wariness of misadventure in the Middle East. Israel, too, he stressed at the UN, knows “all too well the cost of war.” And Israel, too, he said, wants “to give diplomacy with Iran a chance to succeed.” But, he added in the next sentence, “when it comes to Iran, the greater the pressure, the greater the chance” of thwarting the nuclear program by peaceful means. In order that this pressure — crucially including a credible military threat — be maintained, he believes, clear, stark reminders of Iran’s true intentions are crucial.

The prime minister’s message is intended, critically too, for diplomats and decision-makers in the capitals of the world. The policy of combining heavy sanctions with a credible military threat really works, he is repeating. Sanctions are what forced the Iranians to come to the negotiating table. And as long as they keep advancing toward a nuclear weapons capability, he is urging, those sanctions should be increased. It’s a potent message — but one that Obama is unlikely to endorse; at a time of Iranian overtures, and the beginning of engagement, the president is not about to further punish Tehran.

At the UN, Netanyahu notably threatened to intervene militarily, alone, if all else fails. “Israel will never acquiesce to nuclear arms in the hands of a rogue regime that repeatedly promises to wipe us off the map. Against such a threat, Israel will have no choice but to defend itself,” he said.

Yet despite the explicit threat, Netanyahu knows that an Israeli strike — or any strike, for that matter — is not imminent. Iran, as he himself acknowledged, has thus far chosen not cross the red line he drew at last year’s UN General Assembly. Instead, the Islamic Republic is seeking to be a threshold nation — not yet armed with nuclear weapons but equipped with breakout capability. The regime’s current effort to ostensibly resolve the nuclear standoff by negotiations with Western powers, and Obama’s readiness to test the diplomatic route, make an Israeli military intervention in the near future exceedingly unlikely.

Netanyahu would doubtless like have worked with Obama to set red lines on the new diplomacy — a time limit, after which the US would conclude that Rouhani is indeed playing the world for fools. But if any such parameters were coordinated, they were kept behind closed doors. In public, all Netanyahu can do — and he is doing it relentlessly — is mount his charm defensive. And wait.