Hopes that Iran’s passage of key thresholds in its nuclear program will prompt a serious global response continue to go unanswered: The International Atomic Energy Agency reported recently that Tehran has enriched enough uranium for one nuclear bomb – and the world yawned.

While, from Washington to Brussels to Beijing, the world is understandably focused on a financial meltdown that could morph into the deepest recession in decades, Tehran moves ever closer to what President-elect Barack Obama has termed the "game-changer" of nuclear weaponry.

Time is running short to stop Tehran through the "tough diplomacy" that Obama promises, the existing multi-national sanctions that are not hurting Iran’s economy enough to force its leaders to rethink their strategy, or a more robust approach that actually could work.

That robust approach would include restricting Iran’s import of refined petroleum on which its economy depends, freezing the overseas assets of its leaders, providing covert support for democratic reformers who face severe governmental repression and building ties to Iran’s restless population that largely hates the regime and already looks favorably on the United States.

Whether the United States and its allies divert their attention quickly enough, and long enough, from the economic chaos to adopt a plan to derail Iran’s nuclear ambitions will depend on how seriously they take the threat. Here are three reasons they should do so.

President Mahmoud Ahmadinejad, who has his own power base but also enjoys the support of Iran’s Supreme Leader, Ayatollah Ali Khamenei, continues threatening to obliterate Israel, our closest ally in the region, which he calls a "stain of disgrace" and a "stinking corpse." He and other Iranian leaders promise and predict Israel’s coming demise.

Iran’s nuclear program extends far beyond enrichment, making the threat to Israel ever more real. Tehran is investing heavily in long-range and technologically advanced missiles that could blanket the Jewish State as well as the know-how to mount nuclear warheads on them.

Furthermore, Iran’s nuclear program directly threatens not just U.S. allies but the United States itself. Ahmadinejad waxes about a "world without America" that is "achievable," chants of "death to America" arise in Iran’s parliament and at officially sanctioned speeches across the land, and Iran’s leaders seem to believe that nuclear weaponry is their tool to reach that goal.

Specifically, Iran is testing the technology to launch what’s known as an electromagnetic pulse (EMP) attack, detonating a nuclear weapon in the skies above the United States and shutting down the electricity grid on which we depend for virtually all necessities and conveniences.

Across the land, lights would go out, computers would crash and food would rot. The nation would revert to a 19th Century existence, millions would die of starvation and illness and recovery from this devastating attack would take weeks, months – perhaps even years.

The United States and others would have to think twice – at the very least – before mounting pressure against Tehran in response to its aggressive and de-stabilizing activities.

Iran is plenty dangerous to begin with. It is the world’s most active state sponsor of terrorism, and its terrorist clients Hezbollah and Hamas are re-arming themselves on Israel’s border in Lebanon and Gaza, respectively. Hezbollah and Iran also have each built a strong presence in South America, the latter with the help of Venezuela’s Hugo Chavez.

Tehran supplied Shiite militias in Iraq with dangerous weapons to use against U.S. forces, it has sought to destabilize the emerging Iraqi state and it tried (albeit unsuccessfully) to derail the new U.S.-Iraq Status of Forces Agreement. Considering the scale of Iran’s activities across the region, a nuclear-armed Tehran is almost too frightening to contemplate.

Already, at least 10 nations in the region, including Egypt, Jordan and Saudi Arabia, have announced plans to launch nuclear energy programs. They profess to want nuclear energy for peaceful purposes but, in fact, they clearly seek nuclear weapons to counteract those of Iran.

A world with more nuclear-armed nations is a more dangerous world. That those additional nations are located in and around the volatile Middle East makes our potential future that much scarier.

So, yes, the world’s leaders must revive the global economy. But they also must adopt a plan that will prevent Iran from developing nuclear weapons.

They are running out of time to do so.