At any moment, North Korea may fire more missiles, inviting a new round of international sanctions that would achieve exactly what they’ve always achieved to rein in Pyongyang’s reckless actions: Nothing.

As all of us wait to see what comes next, no one in the West knows the intentions of North Korea’s young leader, Kim Jong Un. Most of the world wouldn’t pay much attention to a fledgling dictator of a nation described as a giant gulag except for one thing: North Korea has a growing nuclear arsenal. It commands world attention with its threats of nuclear retaliation against the United States and other enemies.

Thursday brought a chilling new disclosure from Washington: North Korea may have learned how to make a nuclear weapon small enough to be delivered by a ballistic missile.

Now, imagine a world with not one rambunctious and nuke-emboldened North Korea, but two. That is, imagine a world in which the Islamic despots of Iran, too, control a nuclear arsenal. A world in which Tehran can threaten plausibly to “wipe Israel off the map.” A world in which Iran cronies Hamas and Hezbollah are liberated to rain more rockets on Israel, knowing the Israeli response will be calibrated on Tehran’s nuclear capabilities. A world in which Saudi Arabia and other enemies of Iran may embark on crash programs to build their own nuclear-weapons industries.

On the day that Iran declares to the world that it has defied Western red lines and is capable of building its first nuclear bomb, the Middle East will become immensely more dangerous and unstable.

The latest round of international talks with Iran to discourage its nuclear program has fizzled. A decade of these talks has produced nothing. Meanwhile, Iran’s nuclear mastery grows. Tehran is building its capability to make a faster dash to the bomb without detection — known as staging a nuclear “breakout.” Iran could have that capability by mid-2014 or earlier, according to a report from the nonpartisan Project on U.S. Middle East Nonproliferation Strategy.

For the better part of a decade, the United States and its allies have tried to prevent a nuclear Iran in two ways: bribes of increased trade or other incentives to stand down. And strangling economic sanctions. Those sanctions, including a European oil boycott, are crippling Iran’s economy. Inflation rages. Iran’s currency has plummeted. Income from the country’s economic lifeline, oil, has been cut by tens of billions.

But those are broad economic measures; it’s not as if Iranian mobs are in the streets demanding that their government abandon its nuclear ambitions. No wonder sanctions have not yet convinced Iran’s supreme leader, Ayatollah Ali Khamenei, to stop his country’s march into the nuclear club.

But those sanctions haven’t yet been ratcheted to full throttle. They need to be.