For more than 14 months, the U.S. government and people were gripped by the plight of 66, later 52, Americans out of a total population of 225 million. What are the reasons for their captivity having such powerful impact on our times? What is the meaning of the "hostage crisis" for the present and the future?

The first thing to explore is the vast disparity between the scale of the deed and the scale of its repercussions. This paradox of scale provides clues to the true significance of this strange historical event.

There was a serious physical threat -- according to this week's revelations, more serious than was known at the time -- to these several dozen representatives of the United States. But there was never a physical threat to the United States itself, nor was the scale of the threat to Americans as great as has been the case in some other circumstances.

More than 116,000 Americans were taken prisoner in World War II and later returned. More than 4,400 were captured and returned in the Korean War, and about 650 in the Vietnam war. According to the Federal Highway Administration, about 140 Americans per day are killed in accidents on the nation's roads.

The hostages taken in Tehran were diplomatic personnel in a revolutionary country rather than soldiers at war, or motorists in traffic. Yet attacks on diplomatic missions or thier personnel are not unprecedented, either in recent months or earlier times.

Early last year the State Department counted 254 terrorist attacks on U.S. diplomats or dipomatic installations within a decade, including the murder of several ambassadors. It is not widely remembered that while the 52 Americans were being held in Tehran, a terrorist attack on the Dominican Republic's embassy in Bogota, Colombia, resulted in the seizure of more than 50 hostages from 14 countries. Sixteen of the diplomats, mostly ambassadors, were held for 61 days before being released.

Moreover, those who apparently plotted the Tehran takeover -- according to currently available evidence, a handful of students working with a religious adviser -- foresaw no more clearly than anyone else the worldwide consequences of their actions.

"Before the embassy seizure, we didn't anticipate this issue to take such dimensions," said Mohammed Mousavi Kho'ini, who is believed to have planned it. According to his statements last July to a Tehran newspaper, an interview given credence by U.S. government experts on Iran, the idea originated with five to seven revoluntionary Moslem students who brought him their plans in advance for advice and clearance.

Kho'ini, a cleric in his early 40s who was tortured and placed in solitary confinement in 1976-77 by SAVAK, the shah's secret police, said the attack was motivated by American support for the deposed shah and student opposition to internal "deviations" from the Iranian revolution. Kho'ini said he and the students decided not to inform Ayatollah Rubhollah Khomeini in advance in order to avoid placing him in a difficult position. Khomeini, of course, quickly endorsed the takeover after the fact.

From its first hours after the embassy's seizure to today, the consequences of the act were enormous. They included:

In Iran, the triggering of a second phase of the revolution, in some respects a second revolution, bringing down the modernist government in a triumph for more radical and clerical forces.

The political and economic isolation of Iran by most of the developed world as well as the rupture of all of Iran's relations with the United States. The final terms for the hostages' release included the total severance of economic relations between Iran and U.S. financial institutions, which previously were heavily involved in that country.

In the United States, the intense concentration of President Carter and his senior foreign policy advisers on Iran, the subject of more than 100 meetings of the National Security Council or its crisis coordinating committee in less than six months after the embassy takeover. U.S. policy toward nearly every nation in the world was affected by the top-priority effort to mobilize international pressure against Iran.

The buildup of U.S. military forces in the Persian Gulf, today the world's most sensitive and volatile region, and the unsuccessful use of U.S. military power in a fashion that cost eight American lives and further damaged U.S. credibility and prestige in the region and elsewhere.

The resignation, to protest the hostage raid, of secretary of State Cyrus R. Vance. A sudden jump in political support for President Carter during the early months of 1980, when he defeated Sen. Edward M. Kennedy in the Democratic primaries. A sharp decline in support for Carter beginning in the spring of 1980, becoming a major factor in his defeat last Nov. 4, the first anniversary of the embassy seizure.

Historians are likely to debate for a long time what lay behind the powerful impact of the action planned by a handful of anonymous students. Some of the answers, though, are already in view.

Clearly, one reason was the symbolic nature of the event as the culmination of a growing sense of American vulnerability and even impotence. The trend had been in motion since the middle 1970s, following the fall of Saigon and Soviet-Cuban intervention in Angola. The takeover of the U.S. Embassy, in a phrase coined by an ABC television producer named Jeff Gralnick shortly after the event, was seen by Americans as "America Held Hostage" as well asa individual Americans held hostage.

Another reason, cited by the United States throughout the drama, was that the Iranian governmental authorities, such as they were, gave sanction to this violation of diplomatic rules. The fact of terrorist action outside these rules by political, religious or ethnic groups has been a major problem for decades, but the propsect of "outlaw governments" is even more serious, particularly in the age of nuclear weapons.

Beyond these factors, the power of international mass communications was a major factor in the intensity and duration of the sense of crisis. Like the Tet offensive in Vietnam in 1968 and Egyptian President Anwar Sadat's trip to Jerusalem in 1977, the embassy takeover was a highly dramatic and symbolic event within camera range of the television networks and accessible to transmission by ocean-bridge communications satellite.

Both for television and the written press, the plight of the hostages has been by far the biggest story during most of the past 14 months, rivaled only by the presidential election and, to a lesser degree, the Soviet invasion of Afghanistan (where reporters and cameras were quickly barred). And because of the scarcity of public knowledge about Iran and previous U.S. activities there, most Americans lacked much of a framework in which to place the sudden and spectacular event.

A study of Prof. William Adams and Philip Heyl of George Washington University of the past nine years of television coverage of Middle East nations reported that for most of the 1970s the major U.S. networks each had less than one story a month on Iran on their flagship weekday evening news programs. As late as 1978, as the Iranian revolution was developing, each of the networks had less than one story a week on Iran.

The coverage exploded in 1979, especially following the takeover of the embassy. That year the ABC, NBC and CBS evening news programs broadcast 261, 252, 208 stories on Iran, respectively, or close to one story each weeknight brodcast. The total was at least one-fourth higher in 1980, based on still incomplete data.

A similar tabulation for The Washington Post shows 35 articles on Iran in 1977, 134 articles in 1978, 335 articles before the hostage-taking in 1979 plu 476 articles that year after the hostages were taken. In 1980 The Post carried at least 916 articles on Iran, an average of nearly three a day, the great majority of which related to the hostages.

The American people have been inundated with coverage of the "hostage crisis," but most of it, especially on television, was narrowly focused on the embassy compound, the oft-repeated fist-shaking on the street outside and other provocative aspects. Unlike Vietnam, which was to some extent a process of national education about the situation there, most Americans know little more today about Iran and the context of the hostage-taking and hostage-keeping than they did in November 1979.

The top-level, continuous and highly visible concentration of the Carter administration on the hostage problem fed the concentration of the news media and the American people. And the immense public interest, in the view of high Carter administration officials, required the governmental concentration.

Now that the hostages are out of Iran, there are justified second thoughts, within and outside of government, about the threat to the 52 Americans and its powerful impact as the 1980s began. The need for study of what happened is all the more urgent in a decade of international instability, terrorism and disorder.