In the full glare of a global media blitz, summits, more than any other form of diplomacy, require the most careful and deliberate preparation. This is especially imperative when the man who will be sitting across from President Reagan is young, quick- minded, stylish and media-savvy.

How should the president and his top advisers prepare for this meeting, which is filled with both dangers and opportunities? The administration must, I believe, formulate sound and clear positions on such priority issues as Afghanistan, human rights and the proposal for the establishment of nuclear risk reduction centers.

However, the most formidable task cononting the administration is to begin to speak with one voice on its negotiating goals on nuclear and space weapons. The president's recent press conference and other high-level statements indicate that much remains to be done on this score, i.e.:

Did the president really mean to imply that even if the Soviets agree to the U.S. position on strategic nuclear warheads (reducing to 5,000) and the NATO position on intermediate systems, there could be no negotiations on the possible deployment of space weapons until, in the president's words, "if and when such a weapons system does prove feasible" -- in other words, some time in the 1990s? If so, the president should issue clear instructions on this important point to our diplomats, who are conveying another message to our allies, and to our arms control negotiators, who are conveying a different message to the Soviets at Geneva.

Did the president really mean that "the United Statesis still well behind the Soviet Union in literally every kind of offensive weapon, both conventional and in the strategic weapons"? Has the president been informed about the U.S. advantage in submarines, in aircraft carriers, in tactical aircraft, in rapid deployment capabilities, in sea-launched ballistic missiles, in cruise missiles and in bombers? The president must know our weaknesses, but he must also be informed of our strengths.

These are not technical questions; they go to the very heart of what General Secretary Mikhail Gorbachev will be discussing. Fortunately, there is still time for the administration to get its act together.

Any significant arms control agreement between the Soviet Union and the United States will require a serious dialogue on offensive systems and defensive plans. To date the Soviets have been insisting on an SDI agreement prior to serious discussions on offensive weapons. This unacceptable precondition has made any progress impossible. If, however, there isal substance to the proposals for reductions in strategic and intermediate- range offensive systems that Soviet Foreign Minister Edouard Shevardnadze brought to the United States, the burden then shifts to the defense.

Both sides have vigorous defensive research programs. Both sides have pledged their fidelity to the existing ABM Treaty. Neither the United States nor the Soviet Union has, however, begun to come to grips with the compatibility of its strategic defense efforts with existing treaty obligations. Any serious U.S.-Soviet dialogue on defensive plans must begin by examining and clarifying the ABM Treaty on certain key questions and ambiguities. For example: Where is the line between "research" and "development"? Where is the line between a "component" and a "subcomponent" or ''adjunct"? What does it mean to say that a system has been "tested in an ABM mode"? Can exotic SDI programs such as laser and particle beam weapons be developed and tested, or does the treaty restrict these programs to the research stage?

The minimum requirement of any agreement will be that the two parties agree on the interpretation of existing obligations under the ABM Treaty (including the Krasnoyarsk radar). Without this essential understanding, prog other areas is unlikely. With this understanding, a major roadblock would be removed.

On procedural matters, it is essential that the time not be consumed simply by both sides' restating past grievances. Little will be gained if both men spend the entire two days saying, "There you go again." I suggest that the summit agenda be divided into thirds: one-third for reviewing the past, one-third for discussing the present and one-third for a dialogue on the future. Of these three time segments, the second offers the best hope for near-term accords. However, if there is to be a fundamental and enduring improvement in the state of U.S./Soviet relations, the third may be the most consequential. For unless these two men can reach a basic understanding about their respective visions for the future, it is likely that tensions can only be marginally and temporarily eased.

In this regard, I would urge the two leaders to try to arrive at a common understanding on the basic underpinnings of arms control and strategic stability. We have our concept of what is stabilizing, but the Soviets seem to be on an entirely different wavelength. For the past several years, the United States has invested tens of billions of dollars in procuring new strategic systems intended to reduce our vulnerability to a Soviet first strike. To date, the Soviets have not had to grapple with the same concerns, but as the new, more accurate U.S. systems are fielded they will face a "window of vulnerability" problem of their own.

Whether the next generation of U.S. and Soviet strategic weapons eases the superpowers away from a "hair-trigger" launch posture or exacerbates first- strike anxieties remains an open question and can be affected greatly by sound arms control agreements. For this reason, I would hope that both Reagan and Gorbachev might bring their top military leaders with them to the summit and authorize them to engage in a far-ranging discussion of our respective nuclear doctrines, strategy and force postures. Such military-to-military meetings could be institutionalized. Over time these discussions could produce enormous dividends -- a point emphasized by Sen. Carl Levin, myself and numerous other senators.

Finally, it is important to realize that the summit is a government-to-government discussion and dialogue at the highest levels. The president should feel free to bring Secretary George Shultz, Robert McFarlane or Ambassador Paul Nitze in on arms control discussions and invite Gorbachev to do likewise with his top advisers.

If this summit is to be productive and if regularized summits are to follow,st not view the meeting as we would view a televised presidential debate, in which there are instant polls declaring who won and who lost. Reagan and Gorbachev are the leaders of two nations whose military power can determine the fate of the world. Ambassador Jeane Kirkpatrick observed in a recent perceptive article that, "There is room for hope." With careful summit preparation and a thoughtful summit agenda, I agree.