(FORTUNE Magazine) – The U.S. imported more oil in 1989 than in any year since 1979 -- 46% of the nation's demand. The cost -- some $49 billion -- contributed to 44% of the year's trade deficit. And because domestic production is in decline, imports could surge to more than 50% of U.S. consumption by 1992, according to the Petroleum Industry Research Foundation. Says Daniel Yergin, president of Cambridge Energy Research Associates, a consulting firm: ''Oil is a Sisyphean load on the trade deficit.'' The OPEC countries' stranglehold on U.S. imports weakened through most of the 1980s as non-OPEC nations increased production. OPEC took back the lead in 1989 (see chart). But the U.S. remains dangerously dependent -- strategically and fiscally -- on imports, period, whatever their country of origin. Prices of crude have increased recently to about $23 a barrel, but they are still too uncertain to encourage exploration in the continental U.S. At the same time, oil fields that have enormous potential and that the oil companies would invest in are increasingly off-limits. Says Yergin: ''The next bell that is going to ring is the decline in production in Alaska.'' Congress has postponed a bill that would open the Arctic National Wildlife Refuge, a wilderness covering an estimated 3.5 billion barrels of oil. The reason: the Exxon spill at Valdez and the subsequent protest of environmentalists. (For how companies and environmentalists can work together, see Managing.) A clean environment is in everybody's best interest. But whether the ecology is more at risk from on-land pipelines than foreign tankers is dubious.

CHART: NOT AVAILABLE CREDIT: NO CREDIT CAPTION: WHERE THE CRUDE COMES FROM A $49 billion load on the trade deficit