A timely comparison by Andrew Leonard in Salon.com about the relative costs of oil price increases versus existing average tariff barriers between countries. He exaggerates, but the quote he lifts from a Canadian investment bank still seems a useful way of thinking about the cost of oil:

"On average," reports the investment bank CIBC World Markets, "a one percent increase in fuel prices leads to a 0.4 percent increase in total freight rates." In terms of a potential impact on world trade, say the authors of the report, Jeffrey Rubin and Benjamin Tal, "the $30 per barrel increase in crude prices since late 2003 is equivalent to an average tariff increase of 5 percentage points -- more than doubling the current average world tariff rate of 4.5 percent."

And what if oil hit a hundred dollars a barrel? That "would be tantamount to an almost tripling of current tariff rates and a de facto elimination of the entire cumulative tariff reduction of the past 45 years."

Tariff reductions = "trade liberalization." Globalization, meet your nemesis: peak oil. As supplies of cheap oil get tight, long-standing global economic trends could be poised for upheaval.