In 2007, the American intelligence establishment issued a National Intelligence Estimate that claimed Iran was not working toward a nuclear weapon. The finding was criticized around the world and was soon disavowed by the Bush administration. Since then, the evidence compiled by the International Atomic Energy Agency has made it clear the NIE was more a reflection of the post-Iraq caution on the part of U.S. intelligence in which they are reluctant to sound the alarms about potential threats than an actual belief in Iran’s good intentions. The refinement of uranium at increasingly high rates and other clues as to work on the military applications of nuclear technology have reinforced the widespread conviction that it is only a matter of time before the Iranians achieve their goal. The only serious debate has been about when that day will arrive.

Thus, the statement by the head of MI6, Britain’s foreign intelligence agency, that Iran will achieve nuclear capability within two years is sobering news. Sir John Sawyer’s reported remarks give the lie to those who have been attempting to deny the existence of the threat. It also makes clear that whoever wins the U.S. presidency this fall will be faced with a momentous decision that is not being fully discussed in the campaign. Both President Obama and Republican candidate Mitt Romney have said they will not allow Iran to go nuclear. But putting a date on the expected time that Iran will realize its deadly ambition means that by 2014, either man will have to decide whether to use force to prevent Iran from obtaining the means to make good on their pledge to eliminate Israel and to exercise hegemony over the Middle East. Given the utter failure of the president’s feckless attempts at engagement and diplomacy to deal with the problem, Americans must ask themselves whether he or his challenger can be relied upon to act.

Sawyer apparently alluded to British involvement in a covert campaign  — presumably conducted with or alongside U.S. and Israeli intelligence — against Iran was the only reason Tehran hadn’t obtained nuclear weapons years ago. But such tactics cannot hold up a state determined to go nuclear indefinitely. The MI6 head said when Iran becomes a “nuclear weapons state,” at that point, the leaders of both the United States and Israel would have a decision to make about the problem.

While Sawyer said the West would have a choice once Iran is a “nuclear weapons state,” there will, in fact, be very little leeway for action then. Sawyer’s timetable may be correct, but he’s wrong to say the West and Israel have two years to think about what they will do. If they wait until Iran already has nuclear capability, it will be too late. The point that must be brought home to both Obama and Romney is that the schedule for taking action must long precede the day Iran can announce its achievement. If they delay until then, it will be too late. Containment of a nuclear Iran is, as President Obama said earlier this year, an unacceptable option.

Though diplomatic sources are still pretending the P5+1 talks still have a chance of success, Iran has demonstrated it is not interested even in a compromise that would probably allow them to eventually get to their nuclear goal. It’s also clear that though the latest round of international sanctions are hurting the Iranian economy, the ayatollahs believe they can withstand the pressure coming from inside and outside the country to give in. More to the point, with the U.S. granting widespread exemptions to the oil boycott and not even enforcing earlier sanctions on Iran, Tehran remains convinced President Obama hasn’t the will to confront them.

If the United States is to avoid waking up sometime in 2014 to learn Iran has gone nuclear, it will be up to Obama or Romney to convince the Islamist regime it will be attacked if it doesn’t give in. While the use of force is a last resort, time is rapidly running out for any other option.