At the brink?

I know we've been through these alarms before and nothing has happened. This could just be a bluff, but maybe not:

(CBS) A second American aircraft carrier steamed into the Persian Gulf on Tuesday as the Pentagon ordered military commanders to develop new options for attacking Iran. CBS News national security correspondent David Martin reports that the planning is being driven by what one officer called the "increasingly hostile role" Iran is playing in Iraq - smuggling weapons into Iraq for use against American troops.

And this seems to chart out new territory of saber rattling:

Targets would include everything from the plants where weapons are made to the headquarters of the organization known as the Quds Force which directs operations in Iraq. Later this week Iraqi Prime Minister Nouri al-Maliki is expected to confront the Iranians with evidence of their meddling and demand a halt.

If that doesn't produce results, the State Department has begun drafting an ultimatum that would tell the Iranians to knock it off - or else.

Maliki confronting Iran will be an interesting exercise in biting the hand that feeds one, but a gun to the back of his head might make Maliki sink in his teeth. As for the ultimatum, if it is issued it will mean we're at the brink.