There have been some concerning rumblings emanating from Iran over a threatened oil embargo if their nuclear policy is hindered. In the unlikely event that Iran hit the world with an oil embargo, other oil producers will increase their production to steady the world markets.
The other threat is that Iran will disrupt shipping in the Strait of Hormuz, which could cut supplies from Saudi Arabia and other major Gulf producers.
China and some other major energy consumers are opposed to any disruption of oil supplies from the Gulf which would boost oil prices at a time when the world economy is teetering on the brink of recession.
