When the US foreign-policy adviser James Rubin and the CNN journalist Christiane Amanpour met 10 years ago, they began a long-distance courtship that lasted several years. “I travelled 180 days a year,” says Rubin. “Yes, someone did actually count the number of days. At the same time, Christiane was away for long periods in the Balkans and the Middle East.”

Rubin lived in Washington, DC, and Amanpour lived in London. So the world’s geopolitical power couple hardly spent any time together for the next three years. “We used to e-mail and text a lot,” says Rubin. “We talked before and after each trip. We communicated with each other eight times a day.” Rubin’s then boss, the US secretary of state Madeleine Albright, established an office in London that, jokes Rubin, who is now special correspondent at Sky News, “I may have encouraged”.

Their long-distance relationship had all the usual bittersweet hallmarks: hotel-room longueurs, pangs of loss, blissful reunions.

“I have to say that it was pleasantly intensified by the absence,” says Rubin. “The beauty of it was that when we were together, we wouldn’t feel the need to do much, particularly as we didn’t have much time. We would go to a museum, or walking in Hyde Park. In a long-distance relationship, when you do see each other, ordinary life is fantastic.”

Rubin notes that they had the “additional strangeness of seeing each other on television. Somehow it made the distance less painful”.

The long-distance relationship is a consequence of a shrinking world. Once confined to the jet-set few – Sir David Frost, for instance, pioneered the “NyLon” marriage (that is, between New York and London), commuting by Concorde between the two cities – globalisation, geographic mobility and changes in working patterns mean love has a whole new hunting ground, and what was once the sphere of showbiz and the travelling salesman has become a common lot.

“It’s a function of the age we live in,” says Rubin. “It reflects the ease of travel and the ease of communications.” Technology, travel and jobs all play their part.

So recognised are long-distance relationships in the US that they boast a widely recognised term: the LDR. Greg Guldner, the director of the Center for the Study of Long Distance Relationships, estimates that 14m Americans are in LDRs. “People used to meet by proximity: villages, schools or colleges,” he says. This “courting radius” has been augmented by conferences on an international scale, contract jobs and internet chat rooms.

Guldner, a psychologist and a medic in the US army, became interested in the subject while researching a PhD in 1990. “We noticed that half our graduate students were in LDRs,” he says.

A thesis followed, then his institute, aiming to be “a clearing house for information about LDRs”, defined them as relationships conducted over 125 miles or more apart. In the past five years, says Guldner, the LDR has become a hot subject and a micro-genre of self-help literature. There are other centres, including the National Long Distance Relationship Building Institute, and other LDR gurus, including the Canadian writer Stephen Blake, author of Loving Your Long-Distance Relationship.

What about the UK? Well, befitting its status as a transatlantic hub, Britain does appear to be a centre of international romance. A recent survey carried out by Orange Broadband revealed that as many as 1m Britons are currently involved in an LDR. “Our survey showed that about one in five Brits have at one stage had an international relationship,” says a spokesman. “We are witnessing the globalisation of dating.”

LDR research is more developed in the US. Relate, the UK’s largest relationship-counselling service, has no figures on it, nor does the Office for National Statistics. But Guldner estimates that the UK figures would mirror those of the US: 2.9% of married couples. “So if there are 17m married couples in the UK, that would be almost 500,000.”

Further evidence of British distance dating comes from matchmaking agencies such as Parship, whose Penny Lukats says an increasing number of singles actively specify foreign partners. The Orange Broadband survey found Britons to be actively choosing the nationality of their lovers (apparently, British men desire Swedish and French women; British women, on the other hand, prefer Italians).

And the workforce is on the move. Tad Zurlinden of the Association of Relocation Professionals says that the number of people moving for work “has doubled in the last 10 years”. Hence, more LDRs.

If the bicycle was said to have been a significant influence on the gene pool in the 19th century, then cheap flights and the internet have enlarged today’s courting radius by thousands of miles.

“The web has opened new horizons for those seeking long-distance relationships,” says a spokesman for Craigslist, the vast international online classifieds site, adding that many posters specify foreign lovers. “For some reason, British men seem to want American women.”

There is even a small market for specialist devices for those in LDRs, including an internet-enabled vibrator and Wi-Fi wine glasses called “lovers’ cups”, which allow couples to toast each other across the great divide.

Of course, LDRs have existed before, most notably in the military. “They were of great interest during the second world war, and the divorce rate did spike after the end of the war,” says the sociologist Laura Stafford, author of Maintaining Long-Distance and Cross-Residential Relationships. And, as John Costello points out in his book Love, Sex and War: Changing Values, 1939-45, there was a steep rise in extramarital affairs during the second world war, and of the 5.3m British infants delivered between 1939 and ’45, over a third were illegitimate. The folkloric “Dear John” letter, written by the wife to the cuckolded soldier, is thought to have originated amid the relationship chaos of the war. The subject then re-emerged as women began to work. “There was a lot of academic interest in ‘commuter couples’ during the 1970s and ’80s,” says Stafford. But today’s LDR boom is unprecedented.

Yet popular opinion does not favour the LDR. When the singer James Blunt split with his Czech model girlfriend Petra Nemcova, he blamed distance as one of the main reasons for the break-up. LDRs are widely considered a short-term option, with poor prognoses, and the distance dater may be riddled with doubt. London-based Matthew, 46, who expected to move in with his girlfriend of four years in Paris, found that it never quite happened.

“I now see that it was never going to be,” he says, confirming his friends’ opinions that the relationship was doomed. “Everyone thought it wouldn’t work, and it became a fait accompli.” Equally irritating was his friends’ ribbing about the reunion sex: “All those comments like, ‘You’re going to be having a good time tonight.’ That sort of thing gets to be tiresome.”

Seen through a darker prism, LDRs seem fraught: the management of expectations, the mixed feelings towards that bottle of moisturiser left on the bathroom shelf. And, by the way, what is your lover doing without you?

It was possible that such combustible feelings led to a case of LDR rage when Russell Crowe was arrested on assault charges in 2005 after attacking a hotel employee in New York. Crowe explained later on a chat show that he had tried and failed to call his wife in Australia.

The problem is that while the LDR may be growing, it still lacks established protocols. “Long-distance romances have become far more prevalent,” says Seetha Narayan, author of The Complete Idiot’s Guide to Long-Distance Relationships. “But they are not quite common enough for people to have a template to deal with them, unlike phenomena such as single parenthood. LDRs are still in the learning phase.” Rubin agrees: “There is no definitive way to do an LDR.”

Like many of the people who have become interested in the subject, Narayan wrote her book after having a seven-year LDR with her husband. “We both became too highly educated to find jobs in the same place,” she says. “I had a PhD in philosophy, while my husband, David, was an aerospace engineer. Our professional tracks weren’t designed to bring us together. With LDRs, one has to have a portable career.”

She noted from experience that LDRs can present reunion problems. “People idealise their partners in absence and they become a voice in their head, saying only the right thing,” says Narayan. “One man told me that he internalised his long-distance partner’s voice, then experienced real discomfort when faced with her in the flesh.”

Others split up because one partner has a standard of living far higher than the other – a fact that feeds into gender insecurity. “Contrary to what many people think, LDRs seem to make men more depressed and women more liberated,” says Narayan. Also, while Narayan was never worried about infidelity herself, “people in LDRs do worry constantly” – although they apparently shouldn’t.

“Research suggests that LDRs don’t break up at any greater rate than local relationships. LDR couples worry more about infidelity, but they don’t actually cheat more.”

Thus, people in LDRs have to make a decision as to whether it’s worth proceeding. “I went out with a man in Belgium, but it became apparent that it wasn’t going anywhere,” says Emma, a London-based graphic designer. “Perhaps if we’d been in one country it would have worked, but this way, it wasn’t quite there, as neither of us really wanted to move to the other’s country.” They split up.

James Rubin found that his LDR brought its own tests. “The normal frictions come to pass in a long-distance relationship,” he says. “And I really think their success depends on the phase of your life, too. At 28 years old, I coped. Then I reached the point at which the jet lag became cumulative. The worst moments were when we kept waking up at different times.”

Simon Herbert, who met his American wife, Ellen, on the internet before starting a long-distance relationship for several years – he in Newcastle, she in Los Angeles – found that his LDR caused specific strains.

“I can honestly say that it put a tremendous amount of pressure on me to come up with a great time for Ellen,” says Simon. “At first, I took her everywhere. We must have seen all of the northeast of England in a bruising itinerary. Then Ellen said, ‘Can’t we just spend some time alone together?’ I rang up and cancelled the hotels. Sometimes all you should do is be normal. You know, spending your time doing simple things, such as reading books in silence.”

As to the cost of an LDR: the air fares and telephone calls can mount up. “The cost has been brought down by things like Skype [the internet telephone system],” says Guldner. But Matthew, recently liberated from his LDR, says: “The money for fares really was another factor.” Unsurprisingly, mature people in LDRs tend to be in higher economic groups. “Most estimates say about 10% of upper-level executives are in dual-residence marriages,” says Laura Stafford.

We shouldn’t be so negative about LDRs, says Guldner. “People blame the distance,” he says. “But this is what sociologists call an ‘attribution error’. Almost all the research shows that LDRs work just as well as geographically close relationships.” They suffer from a negative public perception: “People always say that long-distance relationships don’t work,” he says. “The reality is that couples in LDRs fight less, because they don’t want to rock the boat.”

Things that would derange the average couple, like a man leaving his trousers on the floor, remain unremarked on in LDRs. And there are other advantages to LDRs, to do with absence making hearts grow fonder.

“My long-distance relationship was incredibly exciting,” says Valerie Weisenreder, 37, who had a London-New York LDR with her husband, Eric. “When we weren’t together, we really missed each other. There’s an amazing feeling when you’re missing somebody that badly.”

This chimes with Laura Stafford’s research, that those in LDRs are more romantic than their “proximate” counterparts – or perhaps, she admits, the “LDR partner’s glasses may just have thicker lenses”.

There is another effect of the LDR, linked to the economic theory called the Alchian-Allen theorem, as explained by the economist Tyler Cowen of George Mason University in the US: that Australians drink higher-quality Californian wine than Californians, and vice-versa, because it is only worth the transportation costs for the better wine. By this token, a long-distance partner expects greater quality and works harder to achieve it.

“We certainly had fun when we met,” says Simon Herbert. “Three or four days together, and we’d be distilling a couple of months’ worth of romantic urges.”

Weisenreder, who had a six-year long-distance romance with Eric, confesses to feeling “an initial nervousness. Sure, if you haven’t seen each other for three months, there is a rediscovery time. But it was never disappointing. They were intense periods”.

With this edge of frisson, it’s unsurprising that some actively seek out long-distance romance. “I spoke to one guy who had had four consecutive LDRs,” says Narayan. “When I asked him why that was so, he said that he enjoyed the poignancy of parting, the separation followed by intimacy – and of course, the fantastic sex.”

Also attractive is the autonomy. LDRs don’t require mutual taste in interior design. You can stay at work as late as you want, go to the gym, and meet friends for drinks on a whim.

A London art dealer, Thomas, who has been in a long-distance marriage to a journalist in New York for 10 years, claims that they both like the arrangement. “You have to be resolute and tolerant,” he says. “And you must communicate. But I know people in the City who talk to their live-in wives less than I do, and while we’d rather be together, it suits us both.”

Equally, Narayan thinks that those in LDRs should have a goal. “David and I decided on ‘project live together’,” she says. “We realised that we were both willing to make compromises. Long-distance couples are often more egalitarian.” They moved to the same place and are expecting their first baby – indicating that LDRs often break at the point of children.

Rubin and Amanpour’s LDR was resolved by marriage and their son, Darius. “When we had a child, I made the decision to leave my job and come to London,” says Rubin, no longer happy to be permanently peripatetic. Here, they live together, and while they travel a lot, they are no longer in an LDR. The struggle, as Guldner says, is between intimacy and autonomy.

“And most eventually choose the former.”

Case studies

Simon Herbert

Simon, 44, and his American wife, Ellen, 47, met over the internet after he had done a sabbatical as an arts curator in New York and needed an expert to negotiate some photographic licences for him. They corresponded by e-mail for five months, and when it was time for him to return to his home town, Newcastle-upon-Tyne, Simon asked Ellen if he could visit her in California. “She said yes. So I flew to Los Angeles.” Simon was delighted when he met Ellen: “She was beautiful,” he says. They began a long-distance relationship, aiming to meet up every two months. “We tried to correspond our timetables, creating ‘business opportunities’ and all that kind of thing,” he says. “After a year and a half, it became very obvious that we were going to be together. The next step was living together.” Ellen had a son in the United States, so Simon moved to be with her and he has lived there happily ever since. “I’ve had to make changes and construct my identity from the ground up, but I was ready for that. It’s been great.”

Danielle Lousky

Danielle, 24, met her boyfriend, Nerya Netanel, 22, a couple of years ago in Israel, where she was a language teacher and he was a student. She is now back in the UK training to be teacher, but the couple are continuing their relationship as they believe in the eventual outcome: that they will live together in one or other of their home countries. “We meet at all the main holidays, which means we meet around every three months,” says Danielle. “There are expensive bills with all the travelling, but we plan to be together for a long time. I like to think the relationship is strong enough to cope.” It’s difficult for them. “I think the fact that we’re young helps. You wouldn’t want to be in this situation for ever.” As to where they’ll end up, Danielle is uncertain. “Sometimes it’s here, sometimes it’s there. Sometimes it’s Australia. There’ll always be a ‘grass is greener’ situation.”

David Dutton

David met his Austrian girlfriend, Ingrid Greitler, through friends in Yorkshire in 2005. They kept in contact until last year, when they started conducting a long-distance relationship. “I didn’t seek it out,” says 48-year-old Dutton, an engineer from Sutton, Surrey. “In fact, I’d previously had a relationship with someone in Berkshire — and that had seemed like a long distance.” But Ingrid said that the international boundary didn’t have to be a problem. As both she and David have dependants in their home countries, they decided to begin a long-distance relationship, using low-cost airlines between London and Ingrid’s home near Graz. “It is working well,” says David, who goes to Austria to see Greitler once every six weeks. “The undemanding nature of it is good. We both know what we want, and it isn’t a relationship where we are living in each other’s pockets.”

They have met each other’s children, but have remained relaxed and open-minded about the future. For them both, the relationship has led to a greater curiosity about life, with the couple going on excursions to lots of different places and sharing information. “I’m learning to speak German, which is very interesting,” David says. “And I never was a great traveller before, so this has been a real breakthrough for me.”

Valerie Weisenreder

A job in New York kept Valerie Weisenreder there while her husband-to-be, Eric, was living in the UK. “We started dating in the summer, then, before we knew it, we had a long-distance relationship,” says Valerie, who is now 37. “Then, the phone was still 32p a minute, and we’d be talking for an hour a day. It was very expensive, particularly as I was just 19 and Eric was 21. As we were so young, we tried to do it as cheaply as possible, doing courier flights, which was the least expensive way to travel back then. Everything was so planned. There wasn’t any of the spontaneity you’d expect from a young couple’s relationship.” She also recalls feeling anxious about reunions —“If you haven’t seen somebody for three months, it’s a bit nerve-racking” — and the issues that this type of relationship raised. “It’s hard work, and you’d always ask yourself if it’s the real thing or not.” She feels it’s a lot easier for people in LDRs now. “The flights are cheaper, calls are cheap or free, and there’s the internet and mobile phones. Still, the same problems raise their heads, I guess.” In the event, the couple’s LDR carried on for six years, until Eric came over to live with her. She remembers her friends being very sceptical. “But then they saw how happy I am with him.”

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