The likelihood of Israel launching an attack on Iran in the coming months depends largely on the degree of support it receives within the United States - though it will need to look beyond the Barack Obama administration for the weight of endorsement it wants. For the signs are that Obama's team does not want a war; even more challenging for its Israeli ally, a second-term victory will earn the president a two-year grace period both to seek a negotiated solution to the Iranian nuclear issue and put serious pressure on Israel to negotiate a settlement with the Palestinians.
This is an uncomfortable situation for Binyamin Netanyahu, and provides the Israeli prime minister with a strong incentive to confront Iran sooner rather than later. The fact that the next election in Israel is due by September reinforces the case for military action by then (see "America, Israel Iran: mediation vs war", 17 February 2012). The awareness of this in Israel explains the sharp reactions from senior politicians there to a warning by the chair of the US joint chiefs-of-staff, General Martin Dempsey, about the dangers of Israel going to war.
Netanyahu will soon speak at the annual conference of the America Israel Public Affairs Committee (Aipac), held on 2-4 March 2012 in Washington. The delegates are likely to offer him greater acclaim than they do Barack Obama, who is also addressing the gathering. But more important than the speeches or the reactions will be the behind-the-scenes discussions the Israeli leader will have on Capitol Hill.
The president is witnessing a prolonged, divisive Republican race at a time when the US economy is showing signs of life and thus boosting his poll ratings. But the news for Obama may be less good than it seems. Both his current potential opponents, Mitt Romney and Rick Santorum, seem determined to press him from the right towards war with Iran; the latter says "Israel shouldn't be leading this [anti-Iran effort]. This is a national issue for the United States… we should be leading this" (see Jeffrey H Anderson, "Santorum talks about Iran" Weekly Standard, 22 February 2012).
This Republican unity may influence the evolving campaign by ensuring a bigger priority to foreign-affairs issues in the campaign than might otherwise be the case. Whoever emerges as Obama's rival for the White House will argue that the president has been defeatist in Iraq and allowed the Iranians to dominate there, while also withdrawing US troops from Afghanistan and failing to stand up to Tehran there too. He is, in short, an appeaser.
Will this line of political attack work? Much depends on the domestic mood, and that isn't easy to call. The quagmire of Iraq, and the number of American troops killed and maimed there, made the war ever more unpopular - so criticising Obama for the withdrawal will work only among loyal Republicans. Afghanistan is harder for the president, because it links directly to 9/11, but Osama bin Laden's death diminishes its importance.
This leaves Iran, which would in normal circumstances attract little attention. Yet a Pew survey for January 2012 which finds 75% support for Obama over the Afghan withdrawal also finds 58% would favour the US's use of force against Iran if that is required to stop it getting the bomb (and only 30% disagreeing) (see Scott Shane, "After 2 wars, drums again beat over Iran", New York Times, 22 February 2012). This sentiment is intimately linked to the substantial backing for Israel in the United States.
There is a conundrum here, however. The popular support for Israel in the US looks stronger than might be expected, given that (for example) the American Jewish community numbers barely 7 million out of a population now over 300 million mark - and that its members tend to vote Democrat. So where does it come from?
A religious war
An often neglected factor here is the reach of evangelical Christian churches in the United States, of which nearly 100 million people are adherents. A significant contingent (perhaps a third) of this huge constituency are "Christian Zionists", whose backing for anything Israel thinks, wants and does is unbending and total: a matter of absolute religious zealotry.
They consider Israel a core part of God's plan for humanity, and its survival an integral part of the "end days" that many evangelicals believe to be imminent. Over the post-9/11 decade they have forged varying links with neo-conservatives and pro-Israel forces in the US - a factor useful to George Bush in the early years of the "war on terror", not least in terminating the Saddam Hussein regime in Iraq (see "Christian Zionists and neocons: a heavenly marriage", 3 February 2005).
But the Christian Zionists see an Iran close to having nuclear weapons, and thus being able and willing to flout God's plan and destroy Israel, as a much greater threat even than the regime which had fired Scud missiles at Israel during the first Gulf war in 1991. Such a nightmarish sequence would clearly be the work of Satan, to be resisted in every way and in the highest interest.
True, this group represents only around a tenth of the American population. But many more evangelicals share its outlook, even if they are reluctant to embrace the latter fully; moreover, they (and Christian Zionists in particular) both are more likely to vote than their fellow citizens and tend overwhelmingly to support the Republican cause.
The combination of all these elements suggests that Barack Obama - whatever his personal views - will be obliged to cede much more than rhetorical ground to those in the United States promoting Israel's perceived interest and justifying an ultra-hard line against Iran. The latter, and commentators on the right more generally, will relentlessly press the theme that Iran presents an existential threat to Israel - and that the only solution is to bomb Iran.
The crafting of this message will be increasingly crafted to strike a loud chord with America's religious right. Indeed, the degree of acceptance in the United States of this aspect of the narrative - that attacking Iran is at heart a religious war, theological justification - will be a crucial factor in the outcome of the crisis.