A dramatic life change - a new job, care for an aging parent, a child custody issue, military service - can impose distance on an existing relationship. And in this age of computer dating and jet travel, it's all too easy to meet a soul-mate hundreds or thousands of miles away. How do couples cope with distance?

There's actually a lot of research on the subject, much of it focused on military couples. Statistically, it appears that long distance relationships are as stable as live-together marriages. And long separations are not necessarily more perilous than short ones. But any long distance relationship raises a whole host of problems - fears, resentments, loneliness - that couples must face, understand, and deal with together.

Many years ago, while on vacation, I met a charming woman. A year after my divorce, I called her - and after months of exchanging mail and phone calls, we began dating. The problem was, we lived 1,200 miles apart - and we both had children who needed to stay put. In spite of career responsibilities, we tried to be together at least once a month. The goal was to get married and live together full time, eventually. But the challenges were daunting. Our kids were jealous. My career suffered badly because I traveled too much. We felt close and warm when together, but we both felt lonely and abandoned when apart. That led to petty fights when we phoned. We simply weren't prepared for the stresses. Five years along, the relationship ran out of steam. However, after much heart-rending talk and some professional therapy, we recently got back together.

Make it work by working at it

My personal experience aside, many couples manage to maintain successful, satisfying long distance relationships over a period of many years. It's easier if you've already lived together in a marriage, and easier still if you have kids together.

Here's some advice, from both experts (book authors -- see links on this page) and my own experience:

• Choose the right time to communicate. Talk often and honestly, but be tactful. If one of you is stressed, the other should be sympathetic and understanding. Impatience never helps. When the job or the kids demand most of the day, the temptation is to talk late at night. It's rarely a good idea to raise emotionally difficult issues when one of you is exhausted. Try to schedule calls when both of you are fresh, cheerful, and rational.

• Write! Writing letters and emails can be more helpful than late-night phone calls. Writing about your own feelings will make you stop and think about your partner's feelings. Reread what you have written before sending it off -- so you can avoid saying something unintentionally wounding. And letters can become treasures. A sweet note or love poem is something your partner can pull out when he or she is feeling lonely.

• Share details in your calls and letters. Talking about people you ran across in your daily adventures, items you've read, or funny stories can help you feel more involved in one another's lives.

• Avoid guilt-tripping. If the separation is getting to you, try not to whine or otherwise express self-pity. It will just make your partner feel guilty. It's probably not only your partner's fault that you're apart -- undoubtedly, you have your own reasons for not being over there. If you're feeling lonely, get yourself out to see friends instead of complaining.

• Find support. Both you and your partner need your own network of family and friends who understand the situation and are happy to keep you company when you're feeling isolated.

• Establish ground rules about other relationships. This is especially important if you are separated so that your partner can pursue an exciting new career opportunity. A new job is itself a time-consuming social challenge, involving new networks and professional acquaintances. Make sure you have an understanding about how "social" these new friendships can be. Of course there are business meals. Are there drinks after work? Movie and theatre outings? When does a new friend become a platonic "date," and is that permissible? Greg Guldner, a physician and psychologist who writes frequently on long distance relationships, notes that "Couples who simply didn't talk about this . . . had more than twice the chance of breaking up (nearly 70% over six months!) compared to those that had clear ground rules."

• Travel often. See each other as often as time and money permit. Statistically, there appears to be no correlation between frequency of visits and long-term relationship success if the couple is communicating effectively. Military couples who are separated for a year or more stay together at the same rate as couples who see each other every week or so. The important thing is to make a good-faith effort, on both sides, to make time for each other.

• Be equitable. Resentments build when one partner feels imposed upon to do all the travel, or all the writing, or all the calling - or all the listening. If one partner has a less flexible work schedule than the other, then an asymmetrical travel schedule might makes sense. But the partners should discuss this openly and reach a clear mutual understanding.

• Put kids first. They have their own rights within the relationship. If one partner is responsible for full-time care of his or her children, then the distant partner needs to make extraordinary efforts to share the work of supporting the kids emotionally and intellectually. The kids need to be part of the communication chain.

• Reach out. Attempting to blend families long distance s may be the most difficult challenge of all. It's natural for a kid to feel jealous when a parent disappears regularly to spend time with a distant partner and perhaps with other children. On the flip side, it's natural for a kid to resent the intrusion of a partner -- perhaps with a child in tow -- who visits sporadically. Unless both partners reach out with heartfelt warmth to each other's kids, sparks will fly. Remember: You're the adult. Forging a relationship with your partner's kid -- and helping your own child to get along with that kid on the rare occasions they see each other -- is your responsibility, not that of the children.