Dramatists thrive on impossible choices; presidents are paid to avoid them. Ever since he took office, President Barack Obama has striven to escape what his French counterpart, Nicolas Sarkozy, once called a “catastrophic alternative”: namely, the stark decision over whether to bomb Iran, or to accept an Iran with the Bomb. As Mr Obama prepares to meet Benjamin Netanyahu, the Israeli prime minister, in the White House today, he will know that, for once, the French leader was innocent of Gallic exaggeration when he framed the looming dilemma in those terms as long ago as 2007. But the man who will sit beside him faces intractable choices all of his own. Having spoken in apocalyptic terms of the threat posed by a nuclear-armed Iran, Mr Netanyahu can never accept such an outcome. That much is determined. But should he therefore order a pre-emptive Israeli strike to remove the danger? Or can he trust Mr Obama to do what is necessary if all else fails? And if all else does not fail – in other words, if diplomacy succeeds and America somehow pulls off a deal with Iran – would any such settlement be acceptable to Israel, or might it amount to a dangerous compromise designed primarily to liberate Mr Obama from his dilemma, at the expense of Israel’s security? Behind all this lies the distinctive psychology that affects any leader of Mr Netanyahu’s nation. The founding purpose of the state of Israel was to prevent the recurrence of two things in particular: an existential threat to a large section of the Jewish people, and that people being forced to rely on outsiders to deal with a vital security risk. Mr Netanyahu will not want to be the prime minister who allows either outcome to occur. Today, then, the two leaders will meet in the knowledge that the decisions they may soon be compelled to take will rank among the most momentous ever considered by the holders of their respective offices. Mr Obama paved the way for their talks yesterday by offering clear words of reassurance to his Israeli guest. Delivering a keynote address to the American-Israel Public Affairs Committee, Washington’s biggest pro-Israel lobby group, Mr Obama came closer than ever before to saying how he would resolve this dilemma. “Iran’s leaders should know that I do not have a policy of containment,” he said. “I have a policy to prevent Iran from obtaining a nuclear weapon. And as I’ve made clear time and again during the course of my presidency, I will not hesitate to use force when it is necessary to defend the United States and its interests.” By ruling out containment in the same breath as he stressed his willingness to use force, Mr Obama subtly but unmistakably hardened his previous formula, which was simply that “all options are on the table”. Paradoxically, he probably believes that this tougher message actually reduces the possibility of war. By reassuring Mr Netanyahu, the president hopes to reduce the chances of a unilateral Israeli strike; by escalating the pressure on Iran, Mr Obama will be calculating that the chances of a diplomatic solution are increased. Yet if yesterday’s speech was for the ears of the pro-Israel lobby, a remarkable interview that the president gave to the Atlantic magazine last week offered a glimpse of how his famously cool head was wrestling with his choices over Iran. This most cautious of leaders made the sober prediction that, if Iran went nuclear, “four or five” other countries in the Middle East would follow suit, triggering what he called a “free-for-all”. “And at that point,” added Mr Obama, “the prospect for miscalculation in a region that has that many tensions and fissures is profound.” At a minimum, the global economy would be thrown off balance and energy supplies disrupted. The risks of nuclear escalation would also be hugely multiplied. If the nuclear-tipped confrontation between India and Pakistan is dangerous enough, a four- or five-cornered arms race in the Middle East would, said the president, “duplicate the challenges of India and Pakistan fivefold or tenfold”. As such, he said, the Iran confrontation was not something that “we’d like to solve: I’m saying this is something we have to solve”. In the interview, the president also showed how the risks of war are preying on his mind. Unlike Iraq or Libya – or any of America’s other recent adversaries – Iran has multiple ways of retaliating in the event of a military strike. Hizbollah, the radical Shia group in south Lebanon, could turn the conflict into a regional conflagration by bombarding Israel with its 40,000 Iranian-supplied missiles. Iran could use its own arsenal of Shahab-3 ballistic missiles to strike Western targets across the Middle East, from the headquarters of the US Fifth Fleet in Bahrain to the high-rise hotels of Dubai. Its navy could seek to close the Strait of Hormuz, through which 35 per cent of the world’s seaborne oil passes every day. Any such assault would almost certainly fail and the waterway would probably stay open – but even a botched attempt would cause oil prices to soar, dealing a grave blow to the global economy. With the uprising in Syria entering a crucial phase, Mr Obama raised another objection to military action. “At a time when there is not a lot of sympathy for Iran and its only real ally is on the ropes,” he asked, “do we want a distraction in which suddenly Iran can portray itself as a victim?” He also showed that he is mindful of the central argument against a pre-emptive strike: that it would only delay, rather than end, Iran’s nuclear ambitions. Any facilities that America destroys could be rebuilt, meaning that war would only buy time – and probably not more than five or 10 years, even on a generous estimate. Hence, Mr Obama told the Atlantic: “It is important for us to see if we can solve this thing permanently, as opposed to temporarily. And the only way, historically, that a country has ultimately decided not to get nuclear weapons without constant military intervention has been when they themselves take [nuclear weapons] off the table.” The president’s words showed that his overriding preference remains to secure a diplomatic settlement. Under a best-case scenario, this would involve Iran permanently giving up its capacity to enrich uranium – although not its civil nuclear programme – in return for a lifting of sanctions and the ending of its diplomatic isolation. So far, so good. But Iran would certainly press for more. If Ayatollah Ali Khamenei, the country’s Supreme Leader, is minded to settle at all – and his public statements suggest quite the opposite – he will insist on formal US acceptance of the legitimacy of his regime and of its wider role in the Middle East. He will also demand the right to continue enriching uranium, albeit at levels that can only be used for civilian purposes, perhaps with safeguards to guard against the manufacture of weapons-grade material. If such a deal were on offer – perhaps via back-channel negotiations that may, at some level, have already begun – would it be acceptable to Mr Obama? And if he chose to agree, how would Israel react, let alone America’s allies in the Arab world? The Sunni kingdoms of the Gulf share Israel’s visceral suspicion of Tehran. Indeed, their own fears are probably greater, thanks to their closer proximity. Saudi Arabia and the Gulf states would probably join Mr Netanyahu’s government in tacit opposition to any settlement that allowed Iran to extend its influence in the Middle East and to continue enriching uranium. Meanwhile, Ayatollah Khamenei’s legion of domestic opponents would feel a sense of betrayal if the US were to accept the legitimacy of Tehran’s repressive, theocratic regime. In short, even if Iran’s leadership decides that it wants to end this confrontation, the highly sensitive business of defusing the situation would still land Mr Obama with more thorny decisions. Every move on this four-dimensional chessboard creates reactions that give rise to still more dilemmas. And in the end, only one man can take the biggest decisions. Mr Obama must either grasp the multiple nettles that have been thrust into his hand, or risk being overwhelmed by a crisis not of his making.