The Kremlin has launched a new propaganda offensive designed to convince governments and peoples in Western Europe of the enormous dangers posed by what is depicted as the erratic, warmongering policy of the Reagan administration.

The campaign, which has been timed to coincide with the countdown to the deployment of U.S.-made medium-range nuclear missiles in five Western European countries starting in mid-December, has been fueled by the U.S. invasion of Grenada and renewed unrest in the Middle East. The message that doing business with Washington has become impossible has been contained in speeches by Kremlin leaders and carried by Soviet envoys to Western European capitals over the past few weeks.

Political leaders and foreign policy analysts in Western Europe are divided over the implications of a sudden heightening in Moscow's anti-American rhetoric, which followed publication on Sept. 28 of a highly unusual statement by Soviet President Yuri Andropov lambasting U.S. policies. While there is a consensus that relations between the superpowers are strained to the point where surrogate military confrontations have become possible, the experts are divided over whether the Kremlin is bluffing when it rules out any hope of improvement as long as President Reagan is in office.

"The Soviets certainly want us to believe that meaningful negotiations with the United States have become useless. Whether or not they are just saying that to scare us is another matter," a senior French official said.

The line that Reagan is a hardened anti-Soviet ideologue who seriously thinks that it might be possible to win a war with the Soviet Union has been elaborated upon by Moscow's emissaries to Western Europe. The envoys have included Georgi Arbatov, director of the Moscow Institute of U.S. and Canadian Affairs; Leonid Zamyatin, head of the international information department in the Soviet Communist Party Central Committee; and Vadim Zagladin, deputy head of the Central Committee's department for relations with foreign Communist parties.

While all three men are regular visitors to the West, their activity over the past few weeks has all the marks of a coordinated Soviet attempt to influence Western European public opinion at a particularly crucial time. It also provides an indication that, despite simultaneous crises in other parts of the world, the Kremlin regards the the battle over U.S. "Euromissiles" as a political and strategic priority.

Western European governments have reacted in different ways to the deterioration of East-West relations while maintaining a common determination to proceed as planned with deployment. The West German government of Chancellor Helmut Kohl has taken the lead in seeking to preserve a dialogue with the Soviet Bloc, while France's President Francois Mitterrand has stepped up his warnings against pacifism.

The French analysis that the gathering trial of strength in Europe is spilling over into the rest of the world was reflected in Mitterrand's comment that the next two months could see the rise of "truly dramatic tensions." Justifying a continued French presence in trouble spots like Lebanon and Chad in a speech in Tunis last week, he said it was essential to "preserve the necessary balances" in order to avoid sliding into war.

Among the objections of Western European governments to the U.S. military intervention in Grenada is the propaganda opportunities this has created for Moscow after a series of reverses. As the influential Paris daily Le Monde put it: "Andropov is seeking to exploit the arguments which Reagan has offered to him on a plate . . . by insisting on the adventurism and unpredictability of the U.S. president."

The Soviet emissaries have used the Grenada affair in their private conversations in Western European capitals as evidence that the U.S. pays little attention to its allies. After being roundly condemned for such acts as the invasion of Afghanistan and the crackdown in Poland, the Kremlin is relishing the Reagan administration's present diplomatic isolation--a prize that would be worth many Grenadas if it could hold onto it.

"Europe is much more important to us than Grenada," a visiting Soviet official said in Paris over lunch. He went on to try to convince his British host that "the Americans will do exactly what they want. Once they fix us, they will get you."

The Western Europeans have been using the opportunity to convey their own messages. A Soviet foreign policy analyst recounted how he had been approached by a senior French official who told him to pass the following information on to Moscow: "However long it takes, we intend to find out who was responsible for the bomb attacks in Lebanon against the multinational force and see to it that they are punished."