How can President Reagan mend fences with the millions of Americans whom he has in effect called dupes for supporting the nuclear freeze? Many of them in Congress and elsewhere have pointed one way: either to retract or substantiate his campaign-trail charges that the freeze movement is manipulated from abroad by ''some who want the weakening of America.'' But to be convincing in the long run Mr. Reagan needs to pursue peace as vigorously as these fellow citizens through the START negotiations and other means he prefers to the freeze.
As it is, he has let the comprehensive nuclear test ban treaty negotiations languish. He has not pushed for ratification of test limitation treaties long since signed. And he has left the impression of being hastened into arms control initiatives by the very movement he says is being manipulated. Does this mean Mr. Reagan himself is a puppet at one remove of those who would weaken America? Obviously not. No one has to be manipulated into seeking peace when devastating nuclear arsenals could be triggered by war.
This does not mean that Moscow's minions have stayed out of the peace movement abroad even while that movement remains harshly suppressed at home. Indeed, communists latch onto and try to influence almost any movement with a good name - labor, liberation, civil rights, peace. But the communists should not be handed such causes on a tray by the abdication - or denigration - of democratic fighters for them.
Mr. Reagan is well within the bounds of responsible campaigning when he attacks the freeze itself as what he considers a threat to security. Part of the debate is whether the US would be frozen in a position of inferiority, as he says, or strengthened through cutting the enormous drain of the arms race.
But Mr. Reagan clouds the issue when he generalizes that the freeze movement is not inspired by ''sincere, honest people who want peace.'' Clarification is in order.