The Independent: Iran's open support for Hamas, coupled with US and Israeli accusations that Tehran has supplied it with weapons, could harden Israeli public opinion in favour of military strikes against Iran whose nuclear programme is seen as an "existential" threat to the Jewish state.
How long will it take Iran to enrich enough uranium to build a nuclear weapon?
Iran's open support for Hamas, coupled with US and Israeli accusations that Tehran has supplied it with weapons, could harden Israeli public opinion in favour of military strikes against Iran whose nuclear programme is seen as an "existential" threat to the Jewish state.
The Gaza assault has provided a reminder that behind the Middle East conflict lies Barack Obama's biggest international challenge in 2009: curbing Iranian nuclear ambitions which, if left unchecked, could change the global strategic balance within months.
With Israeli elections looming, and leading contenders for prime minister refusing to rule out force to stop Iran gaining a bomb, international attention will soon return to Tehran's defiance of the UN by continuing to enrich uranium.
The question is, how long would it take Iran to produce enough stockpiles of low-enriched uranium to break out and build a weapon? If it decided to go the military route, which would contradict its position that its programme is for energy, Tehran would have either to build a clandestine facility (which UN inspectors have not detected) or throw out the inspectors, which it has been loath to do so far.
Independent US and British analysts say that, in a few months, Iran will have accumulated enough low-enriched uranium to upgrade to fuel for one bomb. But as Mark Fitzpatrick, of the International Institute for Strategic Studies, has said: "Being able to enrich uranium is not the same as having a weapon."
According to estimates by the International Institute for Science and Security (Isis), Iran has produced 425kg of low-enriched uranium, or enough to make half the quantity of the 20-25kg of weapons-grade necessary for a crude bomb.
With Iran continuing to add thousands of centrifuges to its enrichment plant at Natanz, it could produce the 700-800kg of low-enriched uranium needed for a bomb "within a few months".
A British independent analyst, Paul Ingram, pointed out that, once Iran does reach the threshold, it would still take many more months before sufficient weapons-grade fuel could be produced. Even if the Iranians do achieve weaponisation, "there is no guarantee that their missiles are capable of delivering," said Mr Ingram, of the British American Security Information Council. "I don't think that 2009 is a make or break year," he added.
But Israel may feel its strategic interests are at stake once Iran reaches "break out" capacity, which could provide an early crisis for Mr Obama. Benjamin Netanyahu said last month that Mr Obama had told him Iran acquiring nuclear weapons was "unacceptable."
But even the US appears to have contemplated a nuclear Iran. The Israeli newspaper Haaretz said last month that Mr Obama would offer Israel a "nuclear umbrella" against the threat of an Iranian nuclear attack by threatening a devastating US response – a policy apparently based on an assumption that Iran would obtain the bomb.