How well do you understand the Soviet threat? Here are a few test questions.

*General Secretary Mikhail Gorbachev's plan to revitalize the economy will . . .

a. Force a slowdown in Soviet weapons spending as civilian industry siphons away skilled labor, materials and machinery.

b. Rejuvenate Soviet arms spending by improving the high-technology industrial base.

*During the next five years, the Soviet Union will probably . . .

a. Spend less for weapons and buy fewer planes, helicopters and missiles than in past years.

b. Continue its quest for military superiority by buying more weapons of higher quality.

*In the realm of advanced military technologies, the Soviet Union . . .

a. Trails the United States in most areas, will have difficulty closing those gaps and may have to watch as new gaps emerge.

b. Trails in some areas but is narrowing the gap.

The answer in each case, according to official U.S. documents, is both of the above. Which is more correct depends on whether you read (a) congressional testimony not designed for general circulation or (b) the Defense Department's glossy volume called "Soviet Military Power," which has an annual printing of 330,000 and is forwarded to the U.S. Information Agency for translation into 10 languages.

The first edition of "Soviet Military Power" was published in 1981. It was, according to the preface to the most recent edition, "detailed, frank and authoritative." The book is distributed to civic groups, U.S. embassies and military commands round the world and any member of the public who requests it.

The most recent edition of "Soviet Military Power," which Defense Secretary Caspar W. Weinberger unveiled at a news conference last week, rarely contradicts other administration statements on the Soviet Union. But the booklet, rich with color photographs and drawings, omits some facts and presents some gray areas as black. In so doing, it often conveys a different impression than other administration documents.

For example, Donald A. Hicks, the undersecretary of defense for research and engineering, notes in his annual technical report to Congress that the United States leads the Soviet Union in 14 basic technologies and trails in none, with the two nations about even in six areas. The Soviet Union has worked hard to redress the balance, the report adds, but with little success.

"It will remain difficult for the U.S.S.R. to close many already existing technology gaps, and new ones are likely to emerge," the report concludes.

"Soviet Military Power" does not include that chart of 20 basic technologies, and it emphasizes a different trend. "While the United States continues to lead the U.S.S.R. in most basic technologies," it says, "the gap in the military application of such technologies continues to narrow."

Similarly, a recent analysis by the Central Intelligence Agency and its Pentagon counterpart, the Defense Intelligence Agency, concluded that Gorbachev's economic program may cause difficulties for the military sector. Some Soviet generals support the initiative because they recognize that advances in computers and other technologies will benefit them, but at the same time it will provoke "intense" competition for engineers and key materials that may slow arms procurement.

"Over the next few years, the defense industries will be expected to do more with the resources they have as they satisfy continuing defense requirements," said the analysis, which was submitted to the Joint Economic Committee of Congress.

"Soviet Military Power," on the other hand, raises the issue of Gorbachev's program only to note that it will contribute to "military might."

"The ultimate beneficiary of Gorbachev's modernization program will be the Soviet military-industrial complex," the book says.

In the longer run -- two or three years from now -- the joint CIA and DIA analysis predicts even stiffer competition between civilian and military sectors.

"At that juncture, shortfalls in industrial modernization and technological advance could increase pressures to postpone certain major defense initiatives -- a development that would be unpalatable to the military and some political leaders," the analysis says.

"Soviet Military Power" agrees that such competition for resources may ensue. But the book harbors no doubts about who will win that competition.

"Gorbachev . . . knows that military strength is the basis of the U.S.S.R.'s existence," the book says. "It is very likely, therefore, that civilian programs will continue to suffer as the Soviet thrust for military technological supremacy focuses on qualitative improvements."

"Soviet Military Power" discusses Soviet arms sales as one tool "to advance the ideological goal of a communist world order."

The book, which is written by DIA officials, does not mention the intelligence agencies' conclusion in congressional testimony that "hard currency arms export fell about 30 percent in 1985 and could fall again this year."

Perhaps the issue of Soviet military spending shows best how different aspects of the same story can be used to different purposes. Thus, "Soviet Military Power" points out that Soviet military expenditures from 1976 to 1985 "greatly exceeded those of the United States."

Hicks' report supports that conclusion. But it says something else: that during the same period, U.S. and NATO military spending greatly exceeded that of the Soviet Union and its allies in the Warsaw Pact