Partly due to Soviet bungling on the Korean jet downing and partly to shrewd new propaganda initiatives in Washington, Ronald Reagan is now virtually in the clear toward achieving his two main foreign policy objectives of the year.
There is every reason to think that he will now get both actual deployment in Europe in December of the new Pershing II and cruise missiles, and funding from Congress for MX.
Opposition to these projects both among European allies and in Congress has all but collapsed in the wake of further changes made this week in the American negotiating position on missiles on top of those changes announced the week before in the President's speech at the UN.
This week's additions to the appearance of flexibility in the American positions were:
* A proposal that both Americans and Soviets destroy old warheads when they deploy new ones.
* A proposal that the US would cut back on the number of nuclear warheads for bombers and air-launched cruise missiles if in return the Soviet Union would cut back on its bigger land-based missiles.
* Appointment to the US delegation for the START talks in Geneva of a Democrat, R. James Woolsey, to keep an eye on the performance of the delegation and to let Congress know whether he thinks that chief delegate Edward L. Rowny presents the new proposals adequately and persuasively to the Soviets.
Mr. Woolsey was an expert on nuclear weapons during the Carter administration. Some Democrats in Congress suspect that the Reagan administration is more interested in wearing an appearance of flexibility on arms talks than in getting an actual agreement with the Soviets. The Woolsey appointment is a concession made to reduce congressional opposition to MX.
This week's new flexibility for the START talks, which resumed in Geneva on Thursday, came on top of the new flexibility in the US position for the INF (intermediate nuclear force) talks the week before.
The impact of the new US proposals was aided by the hard response which Moscow's Yuri Andropov had returned last week to the Reagan UN speech.
Experts on the arms control talks (both START and INF) do not expect that Mr. Reagan's new flexibility will make much difference in the actual negotiations in the immediate future. Certainly no one expects any agreements to emerge from either set of talks during 1984.
The situation regarding arms talks is that the Soviets have gained an improvement in the balance of power in Europe by deploying their new SS-20 missiles. They now have about 350 of these weapons with ranges of just over 3, 000 miles.
In effect, the United States is asking them to give up part or all of their present advantage in return for US agreement not to do what it is proposing to do, but has not yet done.
Among experts it is regarded as unlikely that the Soviets will give up something they have unless or until the US has actually deployed the new weapons in Europe. Deployment is supposed to begin in December.
The Soviets may well figure that they have nothing to lose by waiting until after the deployment. The least they can hope to gain is a propaganda advantage from the fact of the deployment. And there is always the chance that West German governments may give way under street demonstrations organized by the ''peace movement.''
But Mr. Reagan has largely satisfied the requirement of the allies for a credible US negotiating position in advance of deployment. In effect the same has been a condition for agreement in Congress on funds for the MX.
Mr. Reagan has had to make his own concessions to gain the position he is now in of being able to expect both deployment in Europe and MX. His original position, strongly endorsed at the Pentagon and in his own ''conservative'' political community, was to shun serious negotiations until the new weapons were actually in hand.
Not until this season, after nearly three years in office, has he made proposals that might conceivably be regarded as interesting by the Soviets. He was seeking more arms first, on the idea they would improve his bargaining position later.
By this week he had backed far enough away from his opening position to cause concern in the Pentagon and alarm among the ''hawks.'' But he had not backed far enough away to run the risk of serious negotiations in advance of having the new weapons in hand or on the assembly lines.
What does seem to be shaping up is a new round of negotiations sometime in 1984 which will bring together both the strategic weapons talks and those about intermediate weapons for Europe. So far the US and its allies have wanted to keep the two subjects in separate compartments, but that is becoming increasingly difficult.
The reason is that both Britain and France possess strategic weapons, although relatively few in number. Together they have a total of 129 launchers. The US has insisted so far on excluding these from the talks, on the grounds that they are not NATO weapons. But Moscow insists that they are. The US recognizes that sooner or later they will have to be weighed in some way in any new arms control agreements, but where and how.
Although the Anglo-French weapons are primarily factors in the European balance, they are also strategic in size and nature. The increasing likelihood is that all the proposals that are being put forward now to prove flexibility will at some time have to be pooled in one big negotiation covering both intercontinental and European-range nuclear weapons.
The calculations will be so complicated when the attempt is made to pull all this together that an agreement in time for the American 1984 election campaign seems to be entirely out of the question. It seems more likely that the experts will have to beaver away quietly in the back rooms until 1984 is out of the way.
Anyone dreaming of a new arms control agreement between East and West had best put it into a 1985 time frame.