The United States and Israel have publicly displayed radically divergent approaches to the dangers of a nuclear-armed Iran in their biggest policy schism in years.

While President Barack Obama and Prime Minister Benjamin Netanyahu have both vowed to prevent Iran from acquiring nuclear weapons, they have very different views of how to do that. Mr Obama wants a diplomatic resolution through talks on a nuclear deal, while Mr Netanyahu wants Iran to be stripped of nuclear projects before any talk of a deal.

Here's a look at their differences:

What the US wants

- The US, together with Britain, China, France, Russia and Germany, are pressing Iran to reach an accord that would guarantee that Teheran would not develop a nuclear weapon. They are seeking to limit Iran's capabilities without completely destroying its facilities and insisting the country submit itself to inspections.

- The US and some of its allies, notably Israel, suspect Iran of using its civil nuclear programme as a cover to develop nuclear weapons capability. Iran denies this, saying it is for peaceful purposes such as generating electricity.

- The aim of the talks is to persuade Iran to restrain its nuclear programme in exchange for relief from sanctions that have crippled the oil exporter's economy, thereby reducing the risk of war over the protracted dispute. Iran, however, wants complete relief from the international sanctions - anything less is a non-starter.

- The US is looking for the elimination of any ability on the part of Iran to make a nuclear weapon in the future. In an exclusive interview with Reuters on Monday (March 3), Mr Obama said Iran must commit to a verifiable halt of at least 10 years on sensitive nuclear work for a landmark atomic deal to be reached. At the very least, Washington and its partners want to extend the time needed for Iran to assemble a weapon, the so-called breakout time, to be extended to a year in order to provide enough of a gap to react to such a decision.

- In order to increase the breakout time, negotiators say there needs to be a drastic reduction in the number of Iranian centrifuges, the devices used to enrich uranium to the higher level of purity needed for a nuclear bomb. Iran currently has about 20,000 centrifuges, but it has balked at reducing that number to the few thousand that international negotiators are pushing for in any agreement.

What Mr Obama says

"If, in fact, Iran is willing to agree to double-digit years of keeping their programme where it is right now and, in fact, rolling back elements of it that currently exist...if we've got that, and we've got a way of verifying that, there's no other steps we can take that would give us such assurance that they don't have a nuclear weapon...Why would we not take that deal when we know the alternatives - whether through sanctions or military actions - will not result in as much assurance that Iran is developing a nuclear weapon?"

Mr Obama said there was a "substantial disagreement" between him and Mr Netanyahu over how to prevent Iran from acquiring nuclear weapons, calling the latter "unduly sceptical". He pointed out that the Israeli leader had been wrong before with his opposition to a 2013 interim deal with Iran. Under that interim deal, the US and five other powers agreed in principle to let Iran maintain limited uranium enrichment technologies.

"Netanyahu made all sorts of claims. This was going to be a terrible deal. This was going to result in Iran getting 50 billion dollars worth of relief. Iran would not abide by the agreement. None of that has come true.

"It has turned out that in fact, during this period we've seen Iran not advance its programme. In many ways, it's rolled back elements of its programme."

What Israel wants

- Israel wants Iran's nuclear capability to be eliminated, not restricted. It wants Teheran to be stripped of nuclear projects that might be used to get a bomb, something Teheran insists it does not want. Washington deems the Israeli demand unrealistic.

- Israel fears the proposed deal would simply give Iran more time to cheat, or postpone the day when Teheran would have free rein to build a nuclear weapon - something it insists it has no intention of doing. The Israeli leader worries that once an agreement is signed, the US and its allies won't have the political will to use military force, if necessary, to stop Iran from cheating.

- If a military confrontation happens, Israel will face some existential choices. A military strike on Iran's nuclear installations will unleash years of small proxy wars in the Middle East, as well as expose Israel's own population to retaliatory attacks from Iran. In addition, some experts believe if the conflict with Iran does escalate into open warfare, Hizbollah, a pro-Iran militant group, will attack Israel from Lebanon, while Hamas, another group, will do the same from Gaza.

What Mr Netanyahu says

"If the deal now being negotiated is accepted by Iran, that deal will not prevent Iran from developing nuclear weapons - it will all but guarantee that Iran will get those nuclear weapons - lots of them... This deal is so bad. It doesn't block Iran's path to the bomb. It paves Iran's path to the bomb.

"If the world powers are not prepared to insist Iran change its behaviour before a deal is signed, it should at least insist Iran changes its behaviour before the deal expires... If Iran wants to be treated like a normal country, let it act like a normal country."

- In an impassioned speech to the US Congress on Tuesday (March 3), the Israeli Prime Minister pulled no punches in his denunciation of the deal. Mr Netanyahu criticised the two concessions to Iran - the lack of any requirement that Iran destroy its nuclear facilities, and a 10-year expiry date on restrictions. "This deal won't be a farewell to arms, it will be a farewell to arms control... a countdown to a potential nuclear nightmare,'' he said.

He stressed that Iran cannot properly be held in check by weapons instructors and cannot be trusted to respect the restrictions put in place, and that it also could emerge at the end of the decade of restrictions in a stronger financial position to invest in its nuclear armament.

A better deal, he said, would involve a requirement that the nuclear restrictions not be lifted unless Iran changes its behaviour. He added that Iran's regime was "as radical as ever'' and could not be trusted.

When asked about Mr Netanyahu's speech to Congress, Mr Obama issued a stinging rebuttal, saying the Israeli leader had "nothing new", and offered no new strategy for containing Iran's nuclear programme. He also said he did not watch the speech.

SOURCE: REUTERS, AFP, BLOOMBERG, THE STRAITS TIMES ARCHIVES