AS THE psychological warfare over Iran's nuclear ambitions continues, the toughest sanctions yet seem to be biting and cooler heads are calling for calm in the debate about a possible pre-emptive strike against the Islamic republic.
The failure of the United Nations' nuclear watchdog to make any progress in its investigations into Iran's nuclear program has fuelled speculation Israel will argue that Tehran is nearing ''the point of no return'' in its development of nuclear weapons.
The confidential International Atomic Energy Agency report circulated over the weekend shows that since last November, Iran has tripled monthly output of uranium refined to a level significantly closer to weapons grade.
Israeli Prime Minister Benjamin Netanyahu, who will meet US President Barack Obama in Washington next week, said the report's findings confirmed Israel's assessments. ''Iran is continuing with its nuclear program without let-up; it is enriching uranium to a high level of 20 per cent, while grossly ignoring the demands of the international community,'' he said.
But even as news of the IAEA report emerged, many experts were still arguing there was no hard evidence Iran had decided to build a nuclear weapon.
The New York Times reported that the consensus of America's 16 intelligence agencies was that Iran abandoned its nuclear weapon program years ago - consistent with a 2007 intelligence finding and a 2010 National Intelligence Estimate.
As for Iran's recent announcement that it had developed a third or fourth generation of centrifuges, there was genuine doubt they had made it that far, said Mark Fitzpatrick, a non-proliferation expert at the International Institute of Strategic Studies.
Even the top US defence chiefs were talking down Iran's ambitions.
''Iran is unlikely to initiate or intentionally provoke a conflict,'' Ronald Burgess, director of the US Defence Intelligence Agency, told a hearing in Washington last week.
US Defence Secretary Leon Panetta agreed. ''The intelligence has been very clear on this. They continue to develop their enrichment capabilities, but the intelligence does not show that they have made a decision to proceed to developing a nuclear weapon.''
The pressure that Israel says it is under to act comes from more than just a potential threat to its security, warned Bruce Riedel, a former CIA analyst and senior fellow at the Brookings Institution's Saban Centre for Middle East Policy. Mr Riedel said Mr Netanyahu and Defence Minister Ehud Barak faced a fundamental question: ''Do they want to be the Israeli leaders on whose watch Israel loses its monopoly on nuclear weapons in the Middle East?
''Israel has enjoyed a monopoly on nuclear weapons in the Middle East … for at least four decades. That is a strategic and geopolitical position that is obviously to Israel's advantage.''
Experts say the economic sanctions imposed on Iran in the past 12 months are beginning to bite, particularly the restrictions on Iran's central bank and the impending European Union oil sanctions, which are due to come into full effect in June.
Dr Christian Emery, a fellow in the Department of International Relations at the London School of Economics, said the sanctions' success will add further weight to US calls on Israel to scale back talk of strikes on Iran.
''The sanctions are … creating a diplomatic space,'' Dr Emery said, and Iran has stepped into that space by asking for talks with the group known as the P5+1 - the permanent members of the UN Security Council plus Germany.
''My own view is that an Israeli or American strike on Iran is insanity - the last thing we need is another war in the Middle East,'' Mr Riedel said.
''At best it would delay the Iranian program for a couple of years. The disadvantages would be enormous, economically, in terms of a spike in world oil prices at a time that many countries are teetering on the brink of recession, and militarily, in terms of retaliation not just from Iran but from Hezbollah in Lebanon.
''We have international consensus on sanctioning Iran that is remarkable right now, and a war will shatter that with the first bomb.''
Worst case scenario? ''In a worst case scenario we can live with an Iran with nuclear weapons,'' Mr Riedel said. ''Just as we lived with a Soviet Union with nuclear weapons, a North Korea with nuclear weapons and China with nuclear weapons, because the Iranians may be evil, they may be dangerous, but they are not suicidal.''