It is a simple relationship: As Europe's woes fuel the dollar's rise against the euro, dollar-denominated commodity prices fall.

But the malaise runs deeper. The euro zone consumed 10.5 million barrels of oil last year, according to the International Energy Agency. That was down 6% from 2008, but still more than China consumed, and 12% of global demand. Similarly, the euro zone consumes about 15% of the world's copper, much more than the U.S., according to the International Copper Study Group.

A weaker euro will do nothing to revive demand in the region. In dollar terms, oil and copper have fallen this year by 14% and 11%, respectively. In euros, oil is off by only 2%, while copper has risen slightly.

Compounding this is policy. While some might worry that quantitative easing will stoke inflation, the bigger proximate force is deflation, said Charles Dumas at Lombard Street Research, with austerity programs in countries like Greece and perennially tight German consumers. While the euro makes the zone's exports cheaper, its biggest market, the U.K., is weak.

The euro zone's drag extends to that great hope of commodities bulls everywhere: China. China exports as much to Europe as it does to the U.S. The euro's slide against the dollar-pegged yuan makes those imports more expensive at a time when Europeans are tightening their belts anyway. True, commodities are more affordable for China now, but its export markets are weak and Beijing is tightening monetary policy.

Euro-skeptics have long derided the idea of Europe as a major force. Commodities bulls, enduring big falls not just in spot prices but far out along the futures curve, must almost wish they were right.