THE "new world order" that people keep talking about is not yet here, and the shape it will ultimately take is far from clear. With such assorted troublemakers as Saddam Hussein, Fidel Castro, Muammar Qaddafi, and Kim Il Sung still in power, there remain pockets of danger.But with the American triumph in the Gulf war and the decline of the Soviet Union, one thing is clear: Despite doubts and the predictions of US decline, the American era is far from over. If the definition of a superpower is a nation able and willing to project its power around the world, then a case can be made that the United States is now the only superpower. True, the Soviet Union retains an impressive nuclear arsenal, but absent a right-wing coup, its appetite for warfare outside its borders has been curbed. True, Japan must be reckoned an economic superpower, but the Japanese have been timid about asserting anything but economic influence around the world. China has a huge populatio n but is no economic or military superpower, and until it ends its present repression of its own people its international influence will be limited. So if the US retains a world leadership role, the question is how will it use its influence to fashion the shape of things to come? Where should George Bush's vision carry him? It is for the president a dramatic opportunity. He enjoys remarkable popularity and the prospects are good that he will be leading the US, and thus can set its international agenda, through 1996. The priority on that American agenda should be bringing to millions throughout the world that same freedom that is the cornerstone of the American nation. Through the years, US presidents have proclaimed this message of liberty to the rest of the world. First, it is in America's national interest; free nations are less dangerous than dictatorships. But second, the selfless desire that other men and women should be free is something that springs from American hearts grateful for their own democracy. In Bush's first term, there has been extraordinary upheaval for the better. Millions in Poland, Czechoslovakia, and Hungary have shrugged off the dead hand of communist rule. In the Soviet Union itself, though the outcome is less clear, and although factions in Moscow would cruelly repress independence movements in some republics, there is nevertheless opportunity for dissent and for freer expression than has existed in decades. Building on this base, Bush should make the consolidation and extension of freedom a key goal during the remainder of his presidency. This should be no jingoistic message, cast in narrow American terms, but an honest expression of the values of freedom and the free enterprise system to all mankind. It is a message that should continue to be aimed at the Soviet Union, where Mikhail Gorbachev, wary of the right-wing, moves slowly on reforms. It is a message that should be sent to China, whose youth waits in frustration for the crumbling of the repressive old regime. It is a message that must go to Cuba, where Castro, even by communist standards, is trying to thwart the tide of history. It is a message that must be preached even to areas that seem presently unresponsive, particularly the Middle East, now touched by prospects of peace if not of democracy. It is a message that should be supplemented with practical help. The nations of Eastern Europe may be enjoying liberty, but their expertise with the instruments of democracy is sometimes limited. They seek help in running a banking system, in managing independent newspapers, in writing democratic constitutions. There may not be major US government money available for such programs of assistance, but government can facilitate and motivate private enterprise to help. At American embassies around the world, long lines of people wait for visas. America may be criticized, but it is to the US that millions throng to find freedom to grow, freedom to pray, freedom to speak out, freedom to prosper. One of Bush's greatest contributions could be to expand that sense of freedom around the world.