A hard consensus that a new generation of American nuclear missiles will begin to go into Western Europe this year is emerging among leading defense and arms control officials in Bonn, London and Paris, who feel that neither strong Soviet efforts to derail the deployment nor the Soviet-American negotiations in Geneva can now halt the movement toward initial deployment.

For many of these officials, the chief question quickly has become the price the countries that accept the missiles will have to pay in civil unrest.

The stark posing of this question has shifted the debate over the deployment of ground-launched cruise and Pershing II missiles to a much deeper level in Europe than the current discussion in Washington over whether, or when, President Reagan will move away from his opening negotiating position of the zero option. The Reagan proposal calls for canceling American deployment in return for Soviet agreement to dismantle the medium-range missiles that the Russians have targeted on Western Europe.

The differences in the tone and topic of the debate on each side of the Atlantic reflect a far more fundamental difference between European and American policy makers over the nature of the Soviet threat and the best ways to counter it, senior British, West German, French and Italian officials suggested in interviews conducted in allied capitals this month.

The lingering vivid image in Europe of a trigger-happy, nuclear-armed Reagan administration poses as much of an immediate problem for these officials as does the demonstrable Soviet military buildup on their borders.

There is a rising tide of concern in Britain and West Germany in particular that roils a deep reservoir of doubts, criticism and offended pride, not adding up to "anti-Americanism" but calling into question American understanding of European problems.

"We are negotiating with public opinion over this deployment," a British official said in a remark echoed strongly in Bonn and to a lesser extent in Paris, "and that is at least as hard and as important as the negotiations the Americans are conducting with the Russians."

The primary concern in Bonn and London at the moment is minimizing the civil disturbance that deployment may bring as the antimissile movement returns to the streets this spring and summer.

The twin fear is that the Russians are pursuing a strategy at Geneva designed to maximize these disturbances, and that hard-line Reaganites are playing into Soviet hands by the continuing demonstration, in this view, of callousness and confusion on arms control.

President Reagan's quick return to anti-Soviet rhetoric--seen by many here as overly bellicose--in the wake of Helmut Kohl's victory in the March 6 national elections in West Germany has posed the problem of public reaction even more acutely for many officials, who fear that Reagan is reading the German results as having settled a public opinion battle that, for them, has only started.

"Public opinion here will understand that it was some kind of plot, that Reagan has been quiet until now only to influence the German elections," one Kohl adviser worried aloud earlier this month. "He is not a man that Europeans can identify very much with, yet we know he holds a part of our destiny in his hands."

These officials acknowledge that Kohl's triumph has strongly reinforced the likelihood that Pershing II missiles will be deployed on schedule in December in West Germany and the first cruise missiles will be made operational in Britain and Italy about the same time. But it also introduces new dimensions to the issue that they fear are not apparent to policy makers in Washington.

The deepest level of debate here is over Soviet intentions. Rarely voiced publicly, there is a serious view that holds that the Soviet Union has little interest in reaching an interim agreement at Geneva that would allow the United States to begin deployment of the two new missiles while establishing a mutually balanced ceiling for medium-range rockets on both sides.

Such an agreement would mean that the Soviet Union would in effect legitimize the stationing of some of the American rockets, a move that would give Kohl, British Prime Minister Margaret Thatcher and the Italian government a powerful argument in cutting support away from peace demonstrators and politicians demanding that there be no American deployment.

The Russians may well prefer to see no agreement--particularly if European opinion can be persuaded that Reagan is to blame for the stalemate--and the beginning of a deployment that could touch off massive unrest and damage the North Atlantic Treaty Organization's key European member governments, some officials fear.

In this analysis, the first deployment is not the end of the fight for public opinion, but the real beginning.

Reagan's public utterances and negotiating stance should be finely tuned to easing the conditions of deployment, say officials dismayed by the confusion and controversy surrounding the sudden firing of Eugene Rostow and the nomination of Kenneth L. Adelman to replace him at the Arms Control and Disarmament Agency, and by the severe White House reaction to Ambassador Paul Nitze's "walk in the woods" outside Geneva with Soviet negotiator Yuli Kvitsinsky last July.

During that discussion, Nitze momentarily shelved the zero-option idea and put forward on his own a proposal that would have limited each side to 75 missile launchers. Kvitsinsky indicated interest, and according to some reports, the two worked out an idea that would have substituted accelerated deployment of the slower-moving cruise missiles for the Pershing II in West Germany.

The idea was quickly disowned by both the Kremlin and the White House. But the "walk in the woods" formula has become a symbol for European officials of the shape of the most likely agreement that could be obtained at Geneva. Its surfacing has helped spur a second level of debate over the lowest possible level of deployment as opposed to the "full-range" number of 572 Pershings and cruise missiles that Reagan says will be put into Europe unless the Russians agree now to both sides forgoing any deployment.

The current Reagan administration negotiating choice--zero or full range, in arms control jargon--implicitly treats the roughly 600 Soviet SS4, SS5 and SS20 medium-range missiles targeted on Western Europe as an actual military threat that has to be balanced by a roughly equal number of American missiles on European soil. President Reagan's strident denunciations of the Soviet military capability and the ideological evil that drives this buildup reinforce the impression that Washington's response is one-dimensional.

But increasingly European officials describe the Soviet deployment in different terms, stressing their belief that the Russian missiles represent a political and psychological threat that would establish, in Kohl's words during a recent interview, "a broad basis for political blackmail." More importance is attached in Western Europe to the political aspects of the struggle and the need to address the psychological problems posed for a Europe caught between Reagan and Andropov.

"Because of the retaliatory dangers, no one side is likely to attack," British Defense Minister Michael Heseltine said, "either with conventional or nuclear forces. There is certainly an awareness of those dangers on this side, and I am prepared to assume it is the same on the Russian side. I can't see anyone justifying the risk involved by attacking, except in some semifanatical context, and I assume the Russians are not like that. You have to put your mind inside the Kremlin, and ask what they would do."

"We know that the Russian leaders are rational people," echoes a senior West German political figure. "We also know that they can be dangerous, but unlike Americans, we know too that the Russians have lost their ideological thrust and have more than enough of their own problems to deal with. Mr. Reagan's vocabulary on nuclear war is suited for American scenery, not for ours, but when he speaks, it is heard here, too."

Unlike the United States, where Reagan's sharp warnings to the Russians and rocket-rattling speeches are only part of a more general image, there seems to be a high plateau of concern and distrust that was established in the early days of the administration and that has not significantly changed.

"The public impression--although not my own--is that he is trigger-happy," says David Owen, former Labor foreign secretary in London and now a leader of the Social Democratic Party. "He has been a victim of distortion, particularly by our press, but until he delivers an agreement that impression will probably stick."

"It is true that the demonstrations began in earnest in 1981, after those rough early days of the Reagan administation, and not in 1980, immediately after the decision to deploy was taken," added a senior allied diplomat.