US Secretary of State Haig was wise to ignore such critics as Henry Kissinger and keep his appointment with Soviet Foreign Minister Gromyko in Geneva. The date had been set long before the Polish crisis which brought cries that it be canceled. Mr. Haig correctly noted that the need for communication between the superpowers ''does not decline'' in times of tension. Indeed, it is precisely in times of tension that the need for communication increases. To talk for mutual benefit and understanding is not to do ''business as usual'' with the forces of oppression - something that President Reagan properly foreclosed in his State of the Union address at almost the same time. His trade sanctions against the Soviet Union, controversial as they may be, demonstrate what he intended.
Quite different are the diplomatic communications and negotiations that do not mean profit and loss for business but for peace. In this realm are the existing European nuclear weapons talks and the planned efforts to limit strategic arms as in the bygone SALT II round. It was encouraging to hear that Mr. Haig told Mr. Gromyko the US was actively preparing for the renewal of strategic arms talks. Not so encouraging was Mr. Haig's making a renewal of the talks dependent on unspecified conditions, plainly including some sort of improvement in the Polish situation.
Such an approach risks the impression that limiting strategic arms is a favor for Moscow to earn rather than a vital need for the whole world including both superpowers. Moscow and Washington did not let their conflict over Vietnam prevent the concurrent achievement of SALT I. They showed that, while ''linkage'' applies to many international relationships, there must also be at times a ''compartmentalization'' of interests. The latter can permit constructive steps of mutual advantage to be taken even as frictions continue on other matters.
Nuclear arms reductions are of such overriding importance as to justify compartmentalization from issues like Poland and Afghanistan. The US should not give Moscow the opportunity to say that Washington is stalling on a renewal of the talks, as Mr. Gromyko did after the meeting with Mr. Haig.
The fact that the talks went on for almost eight hours, twice as long as expected, suggests that there was a substantial airing of concerns. Mr. Haig indicated he let Mr. Gromyko know of a whole range of Soviet adventurism that troubles the United States. No purpose would have been served by postponing such an exchange until after the Polish crisis. Nor will any purpose be served by keeping a renewal of strategic arms talks hostage to other events.