For Iranian consumers, Turkmenistan's halting of natural gas deliveries to the Islamic republic on Dec. 31 has represented a bitter New Year's present, as the country endures its hardest winter in a decade. The weather has caused 21 deaths, and Iran's northern regions are covered with nearly 2 feet of snow.

Turkmenistan halted daily deliveries of up to 23 million cubic meters to Iran because of "technical problems" and the need to undertake emergency repairs.

The incident has a feeling of deja vu. A year ago, Turkmen supplies were halted before an Iranian-Turkmen agreement was signed, stipulating that the price of Turkmen gas exports to Iran would increase and in exchange the volume of gas exported to Iran would double.

Iran can produce 440 million cu m of gas per day, with domestic consumption consisting of about 380 million cu m, having increased from last year by 12 percent. Because of limitations on the production levels, around 20 million to 23 million cu m of gas were imported into Iran each day from Turkmenistan.

Even more so than the country's oil production facilities, because of 29 years of U.S. sanctions, Iran's natural gas potential remains largely unrealized, despite having the world's second-largest natural gas reserves after Russia and in spite of Iran's efforts to maximize energy exports. Because of massive domestic demand and because U.S. sanctions have largely stymied foreign investment in developing Iran's extensive South Pars gas field in the Persian Gulf, Iran is forced to import about 5 percent of its domestic needs from Turkmenistan via the $190 million, 125-mile Korpezhe-Kurt Kui pipeline, built in 1997. Korpezhe-Kurt Kui's capacity is almost 300 billion cubic feet per year.