When the dispute over Russia's supply of natural gas to Ukraine broke out in late December after Kiev refused to pay the higher prices demanded by Moscow, Europe shivered. Then on Jan. 1, when the gas giant Gazprom turned off the flow of fuel, Ukraine responded by funneling off its required amount from the pipeline transgressing its country on way to western Europe. All across central Europe, energy providers registered a drop in pressure and consumers worried the supply was in danger of being cut.

A gas war -- or at least a war of words and threats -- erupted as politicians in Germany and elsewhere began to question dependency on Russia for a steady supply of gas. Some pointed to alternative sources of energy, while others recommended a return to nuclear energy. The dispute is forcing European governments to face up to the dangers that result from coupling energy policy with foreign policy.

DW-WORLD summarizes the main issues of the gas dispute.