Mahmoud Ahmadinejad
This story hits the trifecta of big stories these days: Greece, oil, and tension in Iran.

Iran has refused to give Greece a shipment of 500,000 barrels of crude oil in a retaliatory measure against European Union sanctions on the Islamic state's lifeblood, oil, the semi-official Fars news agency reported on Sunday.
"Oil tankers that had come to transfer 500,000 barrels of Iranian oil to a refinery in Greece had to go back empty-handed after Iran refused to give the shipment," Fars reported, without giving a source. Oil Ministry officials were not available to comment.

For Greece, this might be a taste of what it would deal with if it ever tried paying for things in the future in Drachma.