The journey was a long one. At each airport -- Bangkok, Hong Kong, Los Angeles -- the seven girls and four boys came closer to "home" from Vietnam. Along with their baggage, most of the children carried a story headed for a happy ending. Along with their names, most of them had an American father who cared.

The pictures of their family reunions, the words of one man who had tenaciously pursued his child across a sea of politics and seasons of red tape, touched me. Yet I kept thinking about the ones left behind.

There are, I am told, anywhere between 8,000 and 25,000 children of mixed parentage unclaimed by American fathers in Vietnam. They are, for the most part, children left behind as easily as umbrellas at a restaurant.

No one knows how many of the sons and daughters ever met their fathers. No one knows how many of the men ever knew of their paternity. Thousands of the children, our Vietnam legacy, were created of the wartime encounters between uprooted soldiers and civilians: men and women. Thousands of the fathers were 19, 20, 21 years old.

It's hard to judge these young, young men sent to war. But it's easy to wonder about the culture that taught them to accept one responsibility and allowed them to slough off another.

What was true in Vietnam under wartime conditions is true in America at peace. After two decades or more of the so-called sexual revolution, two decades of "the pill," young single men are, if anything, less likely to feel responsible for birth control than before.

Parents who once admonished their sons with, at least, the instruction "don't get her pregnant" seem to have fallen silent. The counselors who work with pregnant women report what is common wisdom: it's an unusual male who questions his partner about birth control before the act.

And after the act? Not long ago, a project devised in Pennsylvania to deal with pregnant teen-age girls and their partners floundered because they couldn't get the young males involved. Today that project is for pregnant girls and their parents.

In our lopsided ethics, we used to blame men for "getting" women pregnant. Now we insist that is basically the woman's fault, the woman's mistake, the woman's problem.

The United States has the highest incidence of teen-age motherhood among Western countries, and increasingly these mothers are unmarried. Almost 30 percent of all the babies born to white teen-age mothers and 83 percent of the babies born to black teen-age mothers are out of wedlock.

These children don't bear the stigma of the Amerasians in Vietnam. But they carry their own handicaps. At any point in time, 60 percent of the children born to teens out of wedlock are on welfare.

Our concern for these children is passed on -- to daughters. From every magazine and talk show, we tell our young women today how to get birth control and how to say no. But few young men are told what we want them to know: be caring, be responsible.

The 11 girls and boys who made the recent passage to America through this reunion program are lucky. The 24 on their way are lucky. They are lucky in fathers. So are a lot of our children.

But we do live in a two-track culture. On one track are men for whom fathering has a new dimension, a more powerful commitment to children. Their children are prized.

On the other track are men who sever sex from responsibility. Their tests of manhood don't require a passing grade in carefulness. Their children are no more wanted than an accident.

In Congress last week, we did something that most of the men in Vietnam did not do: we took responsibility for Amerasian children. We admitted a national paternity. In the last hours before recessing, a bill was passed that will make it easier for some children to come "home" to the country of unknown fathers.

But thousands upon thousands will remain unclaimed in Vietnam, marked by their appearance and labeled as "the dust of life." Like a lot of kids in America, they got caught on the wrong track.