Reuters/Tehran/JerusalemAn ally of Iran’s supreme leader called yesterday for Israel to be “punished” for killing a nuclear scientist and the top US general urged his Israeli ally to co-ordinate with Washington as crisis builds in the Middle East. Alarmed Arab neighbours in the Gulf made a plea to scale back confrontation over Iran’s nuclear programme. France, calling on China and Russia to back Western sanctions, said time was running out for diplomacy to deflect Tehran from a course that Washington and Israel have threatened to stop by war. After Supreme Leader Ayatollah Ali Khamenei paid his respects to the families of two scientists assassinated on what Tehran believes were Israel’s orders, one of them just last week, a close ally who is a former nuclear negotiator and currently speaker of parliament demanded retribution. “Terrorism has a long history in some countries like the Zionist regime,” Ali Larijani said of Israel. “The Zionist regime should be punished in a way that it cannot play such games with our country again.” Such threats have been made before in Tehran and it is unclear how or when they might be carried out. Israel, widely assumed to have the only nuclear arsenal in the Middle East, is on guard against attacks on its borders and within, notably by Lebanon’s Hezbollah movement, which is supported by Iran. Israel’s deputy foreign minister has denied accusations that it deployed the hit squad which blew up Mostafa Ahmadi-Roshan on a busy Tehran street last week. But the country has a record of such attacks and is widely presumed by Western analysts to be engaged, along with allies, in a covert war against a nuclear development programme which Iran insists is entirely civilian. Sharp US disavowal of American involvement in the killing has drawn some analysts to see it as a form of rebuke to Israel, amid speculation that President Barack Obama is wary, while he campaigns for re-election in November, that Israel could launch unilateral action that might inflame the region. Obama’s top military official, chairman of the Joint Chiefs of Staff General Martin Dempsey, paid a brief visit to Israel and was quoted by its defence ministry as telling officials there that Washington was keen to co-ordinate on strategy. “We have many interests in common in the region in this very dynamic time and the more we can continue to engage each other, the better off we’ll all be,” Dempsey was quoted as saying in a statement issued by the Israeli defence ministry. The US has led Western pressure on Tehran to curb uranium enrichment that might provide material for weapons. In November Dempsey said he did not know whether Israel would give him advance warning if it decided to strike Iran. Dan Shapiro, the US ambassador to Israel, was quoted as saying on Thursday that the Obama administration would be ready to move beyond sanctions against Iran if they fail to curb its suspected nuclear weapons ambitions. “We know that the sanctions on Iran might fail to work, and therefore we are leaving all the options on the table, as the president has said explicitly, and has instructed the top military officers to do everything necessary to be prepared for any action at any stage,” Shapiro said in remarks at Haifa University that were relayed by a member of the audience.