Among the European allies, it's almost unanimous: now is the time for the United States to come forward with a proposal for an "interim" agreement to break the deadlock in negotiations on the deployment of medium-range nuclear missiles in Europe. Mindful of the political imperatives in Europe, the top people at the State Department agree.

Even Ronald Reagan has been signaling flexibility while holding fast to the "high moral ground" of the Zero Option, which would have the Soviets dismantle their entire arsenal of intermediate- range missiles while the United States would cancel its plans to deploy an offsetting force of Pershing II and cruise missiles in Western Europe.

But hold on. At State, they are already hearing the hoofbeats of the Gang That Couldn't Shoot Straight in the famous fiasco over the European- Siberian natural gas pipeline last year: Defense Secretary Caspar Weinberger, Assistant Defense Secretary Richard Perle (the mastermind) supported by undersecretary Fred Ikl,e, and White House National Security Adviser William Clark (with an assist from counselor Ed Meese).

A battle royal looms, and not just over the narrow issue of how to play a crucial arms control negotiation. The outcome will turn as much on the question of how important it is to bring the European allies along with us in Ronald Reagan's crusade against the communist "focus of evil in the modern world."

Here's the essential background: the North Atlantic Treaty Alliance is operating on the basis of a 1979 "two- track" agreement to begin the U.S. missile deployments on schedule, at the end of this year, while simultaneously seeking an agreement with the Soviets to redress the present imbalance of medium-range nuclear missiles, either by coming down to zero on both sides or by striking a balance--some Soviet dismantling, some U.S. deployment. On the table, as of now, is Ronald Reagan's Zero Option and a Soviet counteroffer that no one on the Western side takes seriously

The first question, then, is who should make the next move? The plain preference of the Pentagon hard-liners is for the United States to stand pat. From public statements, that would appear to be the president's preference as well.

But European leaders have been pressuring the administration to make the first move. Senate Foreign Relations Committee Chairman Charles Percy, echoing the European arguments, is pushing hard for a U.S. first move as a demonstration of good faith. "If civil disobedience is to be minimized when and if the (U.S.) deployments actually begin," Percy said the other day, "the vast majority of the European public must be convinced that we left no stone unturned in our search for a negotiated solution."

So Weinberger and Co. could well lose that argument. But on "Face the Nation" the other day, Weinberger shook up the State Department with a broad hint of what the fallback strategy would be. Asked if he could "conceive of an interim agreement that would be acceptable to you under any circumstances," Weinberger replied: "Well I suppose there might be some-- if the first paragraph was that immediately following the signing of this interim agreement we will reconvene to negotiate the final stage, which is zero."

In other words, the United States should insist that agreement on any interim step be accompanied by a Soviet commitment in principle to an opening U.S. position that the Soviets have flatly rejected.

Much has been made of West German Chancellor Helmut Kohl's recent election--his loss might have undercut any hopes for serious negotiations. But he has made it clear that his ability to face down the West German public's distaste for deployment will still depend on the public perception of U.S. good faith.

The public protest, perhaps accompanied by violence, could well block deployment. But this would not necessarily displease those elements in the administration who set the president up for a fall on the gas pipeline. For what they demonstrated in that episode was a thorough disdain for the value of alliance cohesion and a profound distaste for any accommodations with the Soviets that might lead in the direction of "d,etente."

That's why the struggle over the next move in the "Euromissile" negotiations is only a small part of a larger argument. The politically easier alternative of deploying large numbers of medium-range nuclear weapons at sea; the freedom to act without regard for European sensitivities; the appeal of "global unilateralism" built on powerful naval forces and strategic nuclear weapons--by all that, Ronald Reagan would be sorely tempted. He has a constituency that sees the world that way. And White House advisers put a high premium on that constituency.

So you can't be sure how the developing debate over European missiles will turn out. But there is one hopeful clue: in the heat of the controversy over the pipeline, Ronald Reagan changed his mind when he came face- to-face with the likely consequences of the counsel he originally got from the Gang That Couldn't Shoot Straight.