'FOLLOW THE red line," the voice of the commander in chief commanded. Sure enough, a red line surged "up and up and up" across the television screen. There went Soviet defense spending. "Watch the blue line," the voice demanded, as the "defense share" of the U.S. federal budget squiggled dismally down from 1962 to 1982.

It was the great communicator breaking new ground for the Wizard- of-Oz ("Follow-the-Yellow-Brick- Road") school of presidential discourse. Predecessors have used charts and maps (Kennedy outlining the lay of the land in Laos) or props (Nixon patting the pile of bound transcripts of White House tapes). But unless you count Lyndon Johnson's famous scar, Ronald Reagan is the first American president to use visual aids that squiggle -- the first to disappear off screen while graphics, bearing no hint of source or authenticity, are summoned forth to make the argument.

The Reagan White House has substituted electronics for the traditional art of presidential communication. What I have in mind is the ability, once highly prized in a president of the United States, to talk freely in impromptu discussions -- one-on- one or with small groups, on or off the record -- about the essence and purposes of policy. This president either doesn't have this talent, or doesn't think it's worth having. This president wants to sell his policies, but not to explain them. So, for example, he alone among the seven leaders at the Versailles summit last June declined to give a press conference at the end of the meeting to state the American interpretation of what had happened there.

But perhaps the best evidence is to be found in the way the Reagan administration neglects a select slice of the Washington press corps: the foreign correspondents. For this group Washington is a highly valued assignment; they are an influential crew with an influential readership -- particularly the representatives of the major European papers who keep our allies informed about doings in this crucially important world capital.

Administration officials are quick to complain bitterly about the rampant anti-Americanism they see in the European press. But they seem to be entirely unaware of the many ways their predecessors tried to influence foreign public opinion through the Washington-based representatives of the foreign press.

As a consequence, the pickings have been lean for foreign journalists in the first two Reagan years. An elite group of foreign correspondents formed in the 1950s to meet with American policymakers for background briefings (which remained active through the Kennedy, Johnson, Nixon, Ford and Carter administrations) went out of business early last year after giving up hope of finding open doors to the Reagan crowd.

One of the principal figures in this now-defunct circle reports that he has made no less than 10 approaches to Judge William Clark, the president's national security advisor, without success. Finally, he says, he got a direct answer from one of Clark's minions: "This administration doesn't give a (bleep) about foreign correspondents."

This senseless indifference represents a sharp break from the past. When Secretary of State George Marshall launched the European economic recovery plan in a speech at Harvard, Under Secretary Dean Acheson recalled in his memoirs that he called in "my British friends" -- Leonard Miall of the BBC, Malcolm Muggeridge of the Daily Telegraph and Rene MacColl of the Daily Express. He not only explained Marshall's speech, but asked that they cable the full text and "have their editors send a copy" to the British Foreign Secretary, Ernest Bevin, "with my estimate of its importance."

John F. Kennedy cultivated foreign journalists, some would say to a fault. Not only did he make himself available to a privileged few; he met their needs, and his own, by comprehensive and candid exposition of his policies. Such was his ease in these relationships that his National Security Council advisor, McGeorge Bundy, could exclaim that "this was the only ship of state that leaked from the top." Apart from giving, Kennedy received. He interviewed the foreign correspondents, valuing their slant and perceptions.

Robert McCloskey, when he served in the State Department press office as assistant secretary, recalls that he persuaded Richard Nixon's press secretary, Ron Ziegler, to hire as a permanent member of his staff a spokesman assigned specifically to foreign correspondents. He did the same when Jerry Ford was in the White House. Nixon once was so taken with a column in a London Sunday paper that he invited the author all the way to the White House for an exclusive interview.

In the Carter years, Secretary of State Cyrus Vance met sparingly with news people, domestic or foreign. But Zbigniew Brzezinski, the irrepressible national security adviser in the White House, more than filled the gap. He was the first national security adviser to feel the need for his own press spokesman. And his scrupulous attention to the needs of the White House press corps was matched by a concern for the foreign correspondents -- an awareness of the ways that tending to their needs served his purposes, and the president's. He was not only available to them individually but held regular background briefings for small groups with special interests in a particular issue or region.

The point is not that foreign correspondents now are closed out completely by the Reagan administration. "We still have our own sources, our own private lines to people at State and the Pentagon, and even the White House," says one. "It's a question of how much regular, organized effort the Reagan people are prepared to make -- how much they seem to care."

Not much, seems to be the answer. Or at least not enough to make the sort of special effort that used to be given high priority in the past. Veterans of this business generally agree that indifference to foreign reporters in Washington invites trouble. "The good ones want to understand," says James Greenfield of The New York Times, a former assistant secretary of state for public affairs. "When they're blocked, they take second-bounce material."

When the foreigners -- or the Americans, for that matter -- are blocked, they begin to question the confidence and/or competence of the foreign policy managers at the top -- a scepticism that inevitably finds its way into their reports.

Not making the effort, in short, can only be put down as a mark of wrong-headed indifference, incompetence -- or insecurity.