Mr. Stone's mission

It is good to hear the State Department describing Richard Stone's tour of Central America as primarily a ''listening trip.'' This is what President Reagan's special envoy needs to do - touch base with every country in the region in an effort to open the way to peaceful solution of the widening conflict there. Needless to say, it is difficult to ''listen'' without an open mind, so it can be hoped that Mr. Stone sheds any preconceived notions and approaches his task afresh. This is certainly the spirit of inquiry intended by the Senate, which mandated the appointment of a special envoy in return for appropriation of increased aid for El Salvador.

Mr. Stone's two-week tour comes against the background of rising public concern about the administration's deepening military involvement in Central America and about the sensibleness of US policy. The White House dismissal of Thomas Enders, the State Department's top policymaker on Latin America, and the expected replacement of the American ambassador in San Salvador seem to bode a tougher military posture at the expense of diplomatic negotiation. Mr. Enders, though no soft-liner himself, nonetheless had begun to favor keeping channels open to negotiations with leftist forces in the region. He worried about the United States being drawn into a quagmire. But this all ran counter to views in the White House, above all those of national security adviser William Clark and UN ambassador Jeane Kirkpatrick, who now appear to be carrying more weight than the State Department in steering Central America policy.

Signs of bureaucratic infighting are worrisome. The problems in Central America are of serious magnitude and cry out both for a bipartisan approach toward their solution and for a single, coordinated foreign policy voice.

The experience of the recent past shows how much confusion ensues and how US foreign policy suffers when tensions are allowed to develop between the National Security Council and the State Department. Such confrontation should therefore be strongly guarded against. Now that Mr. Enders has been replaced with a conservative political appointee suitable to the White House, perhaps George Shultz will be allowed to take command of Central America policy as the US secretary of state should logically do. Selection of someone who is knowledgeable about Latin America to fill the US embassy post in San Salvador would also help reasssure those who think American policy may be falling into less experienced hands.

Whatever the personnel changes, however, the basic need of US diplomacy remains clear: it is the need for dialogue in Central America. Dialogue not only with the conservative forces in power but with leftists struggling for social and political change. It would be sad indeed if the United States drove those to the left of center - and far from all of them are Marxists - into the hands of the Soviet Union and Cuba simply because it failed to try to talk with them and to include them in a democratic process of peaceful change. Dialogue and negotiation are what non-leftist countries of Latin America themselves advocate. Should not their voice be heeded?

Mr. Stone has an opportunity to hear that voice and to convey American willingness to cooperate with Mexico, Colombia, Venezuela, and Panama - the so-called Contadora group - in their quest for an end of the conflict in Central America. This does not mean abandoning United States military help to the Salvadorean government. It does mean expanding the possibilities for political and economic diplomacy.