A rare example of the U.S. trying to counter Shiite expansionism instead of tacitly enabling it.

If we end up sending a bunch of Iranian warships to the bottom of the Gulf of Aden, I’m thinking the next round of nuclear negotiations is going to be awwwk-ward.

American warships are prepared to intercept a convoy of Iranian ships suspected of carrying weapons to Houthi rebel forces in Yemen, senior defense and military officials told NBC News on Monday.

An Iranian convoy of freighters, escorted by warships from the Iranian military and Revolutionary Guard forces, appears headed for Yemen, the officials said…

There is no indication that U.S. or other coalition warships have been in contact with the Iranians, but one official told NBC News, “They know we’re there.”

The UN Security Council voted 14-0 last week to impose an arms embargo on the Houthis, which means that the same country we’re expecting to cooperate with UN nuclear inspectors is now openly flaunting its defiance of UN weapons restrictions. And I do mean “openly”:

What’s unusual about the new deployment, which set out this week, is that the Iranians are not trying to conceal it, officials said. Instead, they appear to be trying to “communicate it” to the U.S. and its allies in the Gulf…

U.S. officials say they are unsure why Iran is making the brazen move. One theory they have floated is that the Saudi-led coalition has effectively blockaded any air routes into Yemen and there are no other ways to resupply the Houthis. 

Another theory is that Iran is trying to distract the coalition from another ship it has tried hard to conceal that is currently docked at Oman — a potential land route for smuggling arms into Yemen. 

Yet another theory is that Iran wants to force a confrontation with Saudi Arabia that it believes it will win, because Iran views the Saudi military as weak and suspects the U.S. lacks the willpower to support its Gulf ally.

That’s one possibility. Maybe Iran thinks Obama is so heavily invested now in the success of the big diplomatic nuke kabuki that he wouldn’t dare risk the deal by confronting them with military assets. Not a bad assumption on their part, but maybe O decided that after Lebanon, Iraq, and Syria, letting Iran take over Yemen was a bridge too far. Standing by while Iran resupplies the Houthis might be seen by Sunni nations as the ultimate U.S. betrayal. Another possibility, not unrelated to the first, is that O genuinely fears a hot war between Saudi Arabia and Iran at this point and is calculating that Iran’s navy will be less likely to do something rash if there’s a U.S. carrier group nearby to defend Saudi interests. Tehran and Riyadh have stuck to proxy armies in their skirmishes elsewhere in the region, but Yemen is on the Saudis’ doorstep; if it can be destabilized by Shiite rebels, maybe the Kingdom itself can. If Yemen is the Saudis’ red line and Iran is determined to cross it, Obama may think that using the U.S. navy as a buffer is the only way to keep them apart. For now.

Exit question: Er, is there still a “framework” nuclear deal between the U.S. and Iran? I honestly can’t tell anymore.