Luxembourg takes over the European Community's presidency on Tuesday, with war looming in the Persian Gulf, world trade talks in disarray and Europe in full transformation. The Grand Duchy, a tiny speck on the map with only about 0.1 percent of the population in the 12-nation community, has a good track record in handling the rotating six-month EC presidencies. Jacques Santer, prime minister of the 378,400 Luxembourgers, is convinced the mouse will roar again when his country takes over the community's presidency from Italy as 1991 begins. ``During all of our presidencies we always came up with results,'' Santer said in a recent interview. Five years ago, the Luxembourg presidency paved the way for the Single European Act, an updated constitution that pushes the trade bloc toward creating a truly unified market after 1992. This time around, new initiatives to create economic, monetary and political union by the turn of the century have been thrust into Santer's lap. The Christian Democrat plans to act as a mediator between the EC's powerhouses - Germany, France and Britain - to finalize the blueprint for European unity. ``Because we are so small, the others do not suspect us of having ulterior self-serving motives,'' he said. Shoehorned between Germany, France and Belgium, Luxembourg occupies a key crossroads on the continent, straddling Europe's main cultures - the Romanic and Germanic. It is also well-connected with both the rich north and poor south in the community. The Persian Gulf crisis might prove the first test of Luxembourg's mettle. The EC has said it would not hold talks with Iraqi Foreign Minister Tariq Aziz unless the United States first reaches agreement with Iraq on exchanging foreign ministers' visits. If the EC agrees to talk with Iraq, that task would fall to Luxembourg's Foreign Minister Jacques Poos. During Luxembourg's six months, a lot of energy will be spent on two conferences - one on economic and monetary union, the other on political union -to pave the way for a more unified Europe. Disarray reigns on how fast monetary union should be achieved, Santer said. He said calls for an independent EC defense organization are not realistic and it remains ``essential that we keep a partnership with the United States'' within NATO - the North Atlantic Treaty Organization. The partnership with Washington has been strained in global trade, where the EC has resisted U.S. proposals that it reduce price supports and subsidies for farmers. The agricultural dispute blocked an agreement in world trade talks held in Brussels, Belgium earlier this month. The talks are to resume in Geneva next month. Santer, stressing the progress that has been made in the other 14 sectors covered by the trade talks, said farming should not block an overall accord. He argued in favor of a final deal that, if need be, excludes agriculture.