In their New Year's messages, world leaders looked back with satisfaction at the great changes of 1990 and foresaw a brighter future in the coming year, but they also warned of the hard work still needed to secure prosperity and peace, especially in the Persian Gulf where the threat of war looms.

In his holiday message, Iraqi President Saddam Hussein accused President Bush of aggression and betraying the principles of Christianity and charged Saudi Arabia had abandoned the teachings of Islam.Bush and his Soviet counterpart, Mikhail Gorbachev, in greetings to each other stressed the great strides in mutual understanding, arms control and cultural contacts between the two nations.

Bush praised the Soviet Union for its strong stand in the gulf crisis and for its efforts to undertake political and economic reform.

"I applaud, the world applauds, the decisive action of the Soviet Union in strongly opposing Saddam Hussein's brutal aggression in the gulf," Bush said. The American president also offered encouragement to Gorbachev as he struggles to reform Soviet society.

"I also want to applaud the Soviet Union for the important steps you've taken in building a new society, for the determination with which you are pressing forward with difficult political and economic reforms.

"It's an arduous journey, but one well worth making, for it is a path that leads to a brighter future for your nation."

Gorbachev in his message to Bush heralded the end of the Cold War and improved chances for peace with the removal of the threat of nuclear war but warned of complacency.

"Nations and states have departed for new shores. This road will not be safe and smooth," he wrote. "The international community has run into a serious obstacle at the very start of this road - the aggression in the Persian Gulf. It should find strength to overcome this obstacle to continue the advance toward a peaceful period of civilization."

Gorbachev also acknowledged the turbulent times the Soviet Union was enduring as it pursued the restructuring of "perestroika."

In a message for the holidays issued Sunday, Saddam said, "Iraq was threatened every day by a new type of aggression . . . an aggression demonstrated by the hideouts of evil in the West," according to a dispatch from the Iraqi News Agency.

In Paris, President Francois Mitterrand told the French people peace in the Persian Gulf was possible and pledged France would "work until the end" for that goal.

"With Kuwait occupied, nothing is possible. With Kuwait evacuated, everything is possible," Mitterrand said. "Then the moment for dialogue will open."

In his New Year's message, German Chancellor Helmut Kohl said unification had made 1990 "one of the happiest in German history" and advised Germans to work together to overcome eastern Germany's economic problems.

Kohl reminded Germans not to forget those who had made unification of the two Germanys possible.

"We look back on the ending year with great gratitude," Kohl said. "We will remember the year 1990 as one of the happiest in German history."

He said with German unification completed, Europe must be united to secure peace and prosperity and peace must be maintained outside Europe.

"I think foremost of Iraq's aggression in the gulf," he said. "We all hope that solidarity action of the community of people will make it possible to prevent a war and to reinstate justice in a peaceful way."