The European Union has agreed in principle to blocking imports of oil from Iran, but has yet to decide when such an embargo would be put in place, a decision that could deal a devastating blow to the Iranian economy. 

The EU embargo, as reported by Reuters, comes on the heels of the United States approving sanctions against the Central Bank of Iran. EU countries collectively are the second biggest Iranian oil market after China, buying about 450,000 barrels per day. A diplomat said there still isn't EU agreement yet on any measures against the central bank, as well as disagreement over when the embargo would enter into force, and what to do about existing contracts.

 Iran has threatened to close down the Strait of Hormuz, the oil passage out of the Persian Gulf through which nearly one-fifth of the world's oil travels, if the West imposes economic sanctions. The U.S. Fifth Fleet, based in Bahrain, has said it would prevent Iran from closing the strait.  Iran's parliament also claims to be preparing a bill to bar foreign warships from the Gulf without permission from the Iranian Navy.

Tensions between the two countries continued to rise, after Iran warned U.S. carriers Tuesday to stay out of the Persian Gulf. The Pentagon rebuffed Iran and said the U.S. would not stop its operations there.

The U.S. sanctions, which were included in the Defense Authorization Act that President Obama signed into law last week, would penalize financial institutions conducting business with Iran's Central Bank. Obama took some issue with the provision in a signing statement, indicating there could be some flexibility in how the law is enforced.

Analysts warn that conflict between the U.S. and Iran could cause oil prices to spike. The Saudis have mentioned they would cover any loss from an embargo, a charge Iran hotly denies. They say that while the Iranians are not able to shut down the strait because the United States would stop them, they still have the ability to disrupt the world market.

The world needs to make up their mind if they are going to seriously try to stop the nuclear program, and stick to it. Every day of indecision is another day the centrifuges continue to spin.

Jeff Treesh is @IranAware