The Fourth of July is an instructive time to ponder the evident fact that Americans, who are known in legend and who know themselves for their boldness and self-confidence, are now so often touched by self-doubt and even a bit of self-pity in the conduct of foreign affairs.

The puzzlement is doubled when hesitation -- some call it prudence -- is seen to mark the policy of a president like Ronald Reagan, patriot, woodchopper and the very soul of the American leader who spins a whole political philosophy out of the frontiersman's qualities of independence, courage, self-reliance, survival-mindedness and, not least, the physical capacity to act.

The best 19th-century literature, of course, reveals traits of contemplativeness and insight behind these somewhat crdboard qualities that the political spots and the cigarette ad mannequins keep alive today.

Mark Twain (thank you, James Oliver Robertson, "American Myth, American Reality") warned that people "who Sit in Darkness" had "begun to show alarm. They have become suspicious of the Blessings of Civilization." Writing from Vermont in 1899, Rudyard Kipling advised Americans preparing to take up the "White Man's Burden" that they would be twice judged: coldly by their European peers and also by the "silent, sullen peoples" visited by "savage wars of peace."

Still, for all of our experience and chastening, we resist these lessons and cling to outdated myths of our uniqueness and invincibility. On the contemporary political scene at least, there are recurrent pulses of fear that American power will not be put at the service of American purpose.

It is suggested that our democratic system and our moral nature load us up with inhibitons that do not weigh on less worthy parties. As a result, we fear, our resolve as a nation will be misunderstood, and as a result of that, some great (and unspecified) misfortune will come to pass.

Richard Nixon captured this syndrome memorably when he expressed alarm lest America be taken as "a pitiful helpless giant." It is a sentiment shared by many who did not have his particular ax, or any other ax, to grind.

I do not doubt this is the root of the embarrassment displayed by Ronald Reagan for acting judiciously, refraining from lashing out at the terrorists and using the resources of diplomacy during the Beirut hostage crisis.

Most people seem to think this was the right thing to do. I certainly did. But the president felt an evident need to apologize for his falling away from traditional American direct action. He told us that in private he was pounding the wall.

Some of his partisans could not withhold their alarm, verging on disgust, at his conduct. For a metaphor with which to describe and denigrate it, they reached back to Jimmy Carter, whose manner may have made his actual policy in the Iranian crisis look wimpier than it was.

Among many conservatives, nonetheless, the notion seemed to grow during the crisis that prudence was probably the right course after all. This is a hateful notion for many of them, believing as they earnestly do in the law of retribution and the power of deterrence, not to speak of the almost divine right of Americans to punish pirates anywhere. I suppose they would rather receive it quietly, but they should be given credit and not mocked for having put the national interest first in this affair.

It will be interesting now to see whether Reagan's American critics and the many people he has alienated in Europe will draw from his handling of the Beirut crisis the conclusion that seems fair and logical: that he is not a cowboy, in the crazy sense, and that he has earned respect or his careful management of a situation that no doubt was simpler than the Iranian crisis but that could easily have gotten out of hand.

Reagan and his team are obviously reluctant to call attention to this aspect of his performance, for fear that it will be used against him politically and for fear that it commits him and the United States to a soft line, which may be the wrong line, in a subsequent crisis.

The Fourth of July, however, is not a bad time to observe that the work of building a nation requires many ways, some of them borrowing from American myth, all of them contributing to American reality.