Hillary Clinton's loose talk on Iran

Loose lips sink ships and, for America's top diplomats, they can also sink countries into war.

In early 1950, then-Secretary of State Dean Acheson implied – mistakenly – that the US would not defend South Korea from communist attack. A few months later, North Korea did invade. It took three years and nearly 40,000 lives to end combat.

Last week, Secretary of State Hillary Rodham Clinton suggested the US may extend a "defense umbrella" over friendly nations in the Middle East "once" Iran has a nuclear weapon.

Oops. She didn't really mean it exactly that way, her aides said. But the comment nonetheless suggests President Obama may be ready to accept a nuclear-armed Iran. And, more important, he might counter it with either a missile defense system in the Middle East or perhaps – despite the denial of unnamed Clinton aides – a promise to regional allies of a US nuclear strike on Iran if it ever launched an atomic weapon.

A promise of US nuclear reprisal against Iran would be similar to the "mutual assured destruction" strategy used to contain the Soviet Union. And it would mirror the "nuclear umbrella" the US now provides NATO allies as well as Japan and South Korea.

If the US is no longer hopeful about its diplomatic means to persuade Iran to shelve or abandon its nuclear ambition, that could make Israel all the more trigger-happy to take out Iran's nuclear facilities with a military strike. The likely result? A Middle East engulfed in war.

Israel isn't ready to accept an Iran with nuclear capability, as Obama may be. Israel's very existence is at stake, especially when Iran's president, Mahmoud Ahmadinejad, says Israel should not even exist.

There are other ricochets from Mrs. Clinton's bombshell. Even if the US sets up a nuclear umbrella over Iran's jittery neighbors, such as Saudi Arabia and Egypt, Iran might be willing to risk American nuclear retaliation.

After all, the ruling Islamic mullahs in Iran are driven in part by a messianic Shiite theology, one that supports suicide bombers striking civilians. The regime's founder, Ayatollah Khomeini, once said: "Let this land go up in smoke, provided Islam emerges triumphant in the rest of the world." And the current "supreme" leader, Ali Khamenei, is willing to kill his own people when they peacefully protest a flawed election.

A US umbrella may seem like a good idea on paper. A nuclear-armed Iran could lead to a Middle East arms race, which Mr. Obama warns would be "a recipe for potential disaster." An American nuclear shield might seem to help persuade Arab nations not to develop nuclear weapons.

But if Obama is at all serious about such an umbrella, he would have to implement it immediately – well before Iran comes close to weaponizing its enriched uranium. And such a long-range military commitment would need to have wide bipartisan support in Congress to convince Arab states that the US would be ready for nuclear retaliation for years to come.

Both requirements are unlikely to happen soon, if at all.

Instead, Obama needs to step up diplomatic pressure on Iran (and its enablers Russia and China). A bill in Congress would cut off a vital import – gasoline – for Iran's economy. Tougher sanctions, combined with a wider diplomatic front of nations, is the best way to talk down Iran from endangering the Middle East.

And loose talk of risky alternatives needs to end.