President Obama's Middle East policy has been an ever-worsening train wreck because it lacks credibility and strategy, as Egypt, Libya, and particularly Syria, have shown. And the region is about to get much worse, unless Obama exercises resolute leadership on the most important global security issue of this generation: Iran's pursuit of nuclear weapons.

In a commerce-critical region where "might makes right" and only the strong survive, Iran's acquisition of nuclear weapons could have catastrophic consequences for the Middle East and beyond. The resulting dangers potentially include: (i) nuclear proliferation, as other Mideast countries feel threatened into pursuing their own nuclear programs; (ii) the transfer of nuclear materials from Iran -- the world's chief sponsor of terrorism -- to terrorist organizations and/or rogue states; (iii) bolder attacks by Iranian terror proxies (Hamas, Hezb'allah, Islamic Jihad, etc.) protected by Iran's nuclear umbrella; and (iv) an even more belligerent Iran that flexes its nuclear arsenal to: export its radical Islamic ideology, acquire disputed territories and resources from neighboring countries, and/or undertake actions like blocking the Strait of Hormuz to increase the price of oil.

As Israel's Prime Minister, Benjamin Netanyahu, recently told CBS News's Face the Nation, the Islamic Republic is now dangerously close to a nuclear capability. Because Iran has stockpiled about 190 pounds of 20% enriched uranium, Iran is just 60 kilograms -- potentially just weeks -- short of crossing the nuclear "red line" that Netanyahu set in his speech before the UN last September.

Unfortunately, Obama has signaled no urgency over Iranian nukes. Perhaps he hopes for a negotiated settlement to the issue, now that Hassan Rouhani, a so-called "moderate," was elected to assume Iran's presidency next month. But hope is not a strategy with the Iranian regime. Rouhani has been linked to the 1994 terrorist bombing of an Argentine Jewish community center that killed 85 people, and has boasted about how he manipulated nuclear talks with the West about a decade ago to expand Iran's nuclear program. More importantly, Iran's foreign policy is set by Ayatollah Ali Khamenei, who has banned concessions to the West. Indeed, Fereydoun Abbasi-Davani, the head of Iran's atomic energy agency, made it clear last Friday that Rouhani's election will have no impact on Iran's nuclear enrichment activities.

Obama must also recognize that the sanctions against Iran have demonstrably failed. The Islamic Republic has skillfully outmaneuvered them, as shown in a leaked U.N. report detailing 11 instances of Iran violating sanctions, including attempts to acquire materials for its atomic program. Reuters published an expose outlining how Iran exploits sanctions loopholes to import ore from Germany and France that could be used for making armor and missiles. More importantly, the Iranian nuclear weapons program has never once stopped because of sanctions. The only time that Iran ever suspended its nuclear program was after the U.S. invasion of Iraq, when Iran briefly feared that a U.S. attack was imminent.

Obama's Iran policy has thus far failed to produce any credible deterrent. It's time for Obama to build on the lead of Canadian Foreign Minister John Baird, who warned last month that Iran only has only a few months to demonstrate to the West that it is serious about a negotiated solution to the standoff.

Israel doesn't have the luxury of treating its red lines the way Obama has treated the one he set for Syria's use of chemical weapons; that means that the volatile Middle East of today could become far more engulfed in war and instability. Netanyahu's latest message may be the canary in the coalmine giving its final warning, so Obama should provide bold leadership on this critical issue before it's too late. New Jersey-sized Israel survives only by the strength of the military force that it projects. Critical to that deterrent is making good on its threats, as Israel did with its destruction of the Iraqi and Syrian nuclear programs, in 1981 and 2007, respectively, and its ongoing surgical airstrikes to prevent Syria from transferring game-changing weapons to Hezbollah.

Given such exploits, isolationists might wonder why the U.S. should bother; let Israel bear all of the costs and risks of eliminating the Iranian nuclear threat for us, goes the thinking. But the nuclear program in Iran is far more dispersed, hardened, and distant than what Israel neutralized in Iraq and Syria. Iranian nukes are truly vulnerable only to U.S. military capabilities. Expecting Israel to do the job is like a heavyweight-boxing champion asking his featherweight friend to defend him against the approaching middleweight champion. Such cowardly tactics needlessly endanger the featherweight ally, but -- more importantly -- there is a good chance that the middleweight won't be fully neutralized and will feel far more emboldened to attack the heavyweight after he concludes (alongside the rest of the world) that the heavyweight is just a paper tiger.

Iran can already attack U.S. interests across the Middle East and Europe. And as early as 2015, Iran could develop and test ballistic missiles that could strike the continental U.S., according to a Pentagon report released last week ("2013 Ballistic and Cruise Missile Threat Assessment"). Obama can wait for the U.S. to be drawn into war with a nuclear-armed Iran, or he can proactively address the threat before Iran acquires nukes. But he cannot hide from the threat or hope it away. Obama must lead -- before Iran's nuclear recalcitrance forces Israel's hand, with potentially apocalyptic consequences.

Noah Beck is the author of The Last Israelis, an apocalyptic novel about Iranian nukes and current geopolitical issues in the Middle East.