I went off on holiday just after President Reagan delivered an earnest assurance to America's European allies that he really does want an agreement on arms control.
I come back from my holiday and find Vice-President Bush, himself in Europe, doing the rounds, and repeating ever so earnestly that he and the President really do seek agreements on arms controls.
Apparently some credibility has been regained during the intervening time. Not all people in all the allied countries doubt the sincerity of Mr. Reagan's devotion to arms control. He made headway, apparently, by his explanation on Jan. 14 that he wanted to build ''leverage'' before opening negotiations.
That makes sense. The Soviets are realists. They make deals on such things as arms control on the basis of what they regard as ''the correlation of events.'' There would be little point in trying to get from the Soviets a better position in an agreement than one is prepared to pay for.
That means that one must negotiate on the basis of the weapons one has plus the weapons one is actually building. If what one has or is building is something the Soviets would rather have put aside, they will bargain.
The proof is immediately at hand. The United States is building Pershing II and cruise missiles, intermediate-range weapons designed for deployment in the European theater. The Soviets would rather these new weapons not be deployed. That is what all the coming and going is about.
Incidentally, these weapons were requested by the European allies of the US. The original idea to have them and to put them in Europe came from them, not from Washington. Washington agreed to build them and deploy them at their initial request. This fact tends to be overlooked or forgotten in the current debate.
Also, the request, response, and decision to build all occurred while Jimmy Carter was in the White House. This is another fact overlooked now at the White House where Mr. Reagan prefers to talk as though no one thought of building new weapons until he came along.
The European governments all know these often overlooked facts and understand them. They also still want those weapons deployed in Europe unless the Soviets agree to a fair reduction in the new Soviet missiles which are deployed in Europe.
But the European governments will not dare to accept the weapons they want unless their public opinions can be brought around to believe that President Reagan would sincerely prefer a fair agreement on arms limitations and controls.
And while some progress has been made in persuading the European governments of Mr. Reagan's sincerity, the battle is far from won.
The plain fact is that the rhetoric of the Reagan administration, in particular the things said over the past two years by Mr. Reagan and his secretary of defense, Caspar Wein-berger, have built up a massive doubt about its true preferences in such matters.
In the opinion of some of the wisest experts in such matters the task of persuading European public opinion is still formidable. It is by no means certain that Mr. Reagan's ''peace offensive'' can overcome the legacy of two years of contrary words, deeds, and actions. Until Jan. 14 of this year Mr. Reagan was talking and acting like a man who believed that he would force the Soviets into economic bankruptcy by outbuilding them in the arms race.
It is only since Nov. 13 that he abandoned his attempt to mobilize the NATO allies for a campaign of economic sanctions against the Soviet Union. So far as the Europeans could see, the grand strategy of the Reagan administration was to wage economic warfare against the Soviets, not negotiate with them.
Also, it is known in diplomatic quarters that there was no agreed American position on arms negotiations up to the time Eugene Rostow was fired as director of the Arms Control Agency on Jan. 12.
The claim to want an arms control agreement with the Soviets is not even a month old yet. It takes time for a new position to be recognized and accepted as valid. Deeds will have to back up the new words before the allies are fully convinced. Mr. Reagan does not appear yet to understand that a foreign policy to be effective must be well planned and pursued diligently and consistently over months, and sometimes even years.