Italy and Spain depend on Libya for as much as 22 percent and 13 percent of total crude consumption, respectively, a supply not easily replaced on short notice.
Without alternative supplies of energy to offset it, a decline in oil production would send shock waves through the world, rattling economies and politics alike.
Experts fear the credit crunch will discourage governments worldwide from turning to taxpayers for assistance in climate-change efforts.
A growing number of lawmakers are calling for energy companies to pay for fuel costs borne by poor Britons.
Protests have rocked London, Paris, and other cities across the continent this week.
Iraq's oil minister says the assault helped curb oil smuggling.