It has been considered axiomatic that little can be done to slow the progress of global warming without U.S. leadership. Yet one by one the countries of Western Europe and Japan are adopting explicit national goals to cut their emissions of greenhouse gases. Without intending to, or even fully realizing that it has done so, Europe has assumed the mantle of international leadership on this central environmental issue, leaving the United States increasingly isolated.

Greenhouse warming is caused by the accumulation of several gases in the atmosphere, most importantly carbon dioxide. Since carbon dioxide is the inevitable outcome of burning a fuel, the question of what to do about greenhouse warming is largely a matter of energy policy -- except where there is large-scale deforestation. The choices at issue are how much energy a country needs to grow on (largely determined by the efficiency of energy use), and what mix of fuels will supply it (nuclear, solar and other non-fossil sources produce no carbon dioxide; of the fossil fuels, coal produces the most and natural gas the least).

West Germany's greenhouse-control target is the most ambitious. It intends to cut the country's carbon dioxide emissions by 25 percent from 1987 levels by 2005. Government spokesmen have noted that the comparable figure for a united Germany would be even higher, since energy waste in East Germany offers so many possibilities for easy cuts.

The German announcement followed earlier goals set by Britain, the Netherlands, Denmark and Canada. Denmark plans a 20 percent cut by 2005. The others intend to stabilize their carbon dioxide emissions at 1990 levels sometime between 1995 and 2005.

The means by which these goals will be met are still to be worked out, but the goals have been set -- often after fierce internal debate -- feasibility studies have been done and planning processes are in place. Each of these countries has concluded not only that greenhouse warming is a real phenomenon but that present scientific understanding, while riddled with uncertainties, is nonetheless adequate to merit launching a major policy response.

Recently Japan, which had heretofore followed the U.S. lead on greenhouse policy, announced that it too will stabilize carbon dioxide emissions ''at the lowest possible level'' by 2000. The precise target and program for doing so are to be announced by early autumn. France also is debating cuts in emissions, and the European Community as a whole may not be far from agreement on a stabilization goal. At the last vote, only Spain, Greece and Portugal were opposed.

What makes this trend particularly noteworthy for Americans is that most of these countries are already twice as energy-efficient as the United States. That is, they consume half as much energy to produce a dollar of GNP as do we. Put another way, the United States would have to cut its energy use by an astounding 46 percent without any loss of GNP to reach Germany's present energy efficiency, and then by an additional quarter to reach its planned level.

U.S. greenhouse policy remains as it was articulated at the disastrous international conference sponsored by the White House in April, namely that scientific uncertainties are too great to justify a serious effort to control carbon dioxide emissions, but that further research is a high priority. The United States continues to do the lion's share of basic research on greenhouse warming, but its carbon dioxide emissions are rising each year, and progress toward the articulation of any national energy policy, let alone one that might incorporate greenhouse goals, is questionable. The Department of Energy has been directed by the White House merely to send over options rather than recommendations when it finishes two years of work developing an energy strategy at the end of 1990.

If Japan and the West Europeans are correct and the greenhouse phenomenon proves to be a trend that must soon be reversed, their recent decisions to begin moving in that direction could hold bad news for U.S. economic competitiveness. The means by which carbon dioxide emissions will be cut depend on advances in energy supply technologies, in transportation, agriculture, industry, appliances, building construction -- in short in every corner of the economy where energy use is important. An international agreement to control greenhouse warming would dramatically change criteria of choice in the international marketplace.

The United States is already far behind in many respects, especially in the automobile industry. If the emissions goals now being set elsewhere are met, the gap will steadily widen. Moreover, technological innovation, at which the United States is still pretty good, will generally be the easy part. Commercializing the new technologies, changing social patterns and mobilizing political commitment, in all of which we have recently lagged, will be the key to success.

United States leadership on greenhouse control is no longer an option. The question is whether we or Europe and Japan have the more prudent approach to global warming, and if the latter, for how long -- and at what economic cost -- we will be playing catch-up.

The writer is vice president of the World Resources Institute.