The same techniques that keep marriages strong, says therapist Harville Hendrix, can end conflict between nations. It starts with trying on someone else's reality.

Falling in love is like a temporary inoculation against reality. It's about idealized feelings between two people in which they see connections ("You like the color blue, too!") rather than distinctions. But there comes a time in most marriages when the oneness shatters. "That phenomenon is what I've been addressing for many years," says Harville Hendrix, PhD, a marital and relationship expert and the author of Getting the Love You Want.

For most couples, the romantic interlude of a new relationship leads to an inevitable truth, says Hendrix—"a slow discovery of the other as 'not the person I thought he was.' The breaking of that illusion is one of the most shocking and terrifying experiences of married life. There's an actual change in brain chemistry—levels of dopamine fall while levels of adrenaline and cortisol rise—as people go from excitement to frustration, fear, conflict, and opposition." In the power struggle, partners move from courtship into coercion, trying to get each other to surrender their "otherness." "This is the second stage of all relationships," Hendrix says. "It's not a pathology." But it's when damage can occur to a couple's children and when the couple often splits up.