I think you're on to something where you say, "even where the right course is to reveal the truth that hurts the friend, we should admire people who feel torn about it." This is what has been so missing--among other things--in the case of the unfortunate Ms. Tripp, some element of interior agony: "This was the hardest thing I ever had to do. I hated having to do it, but I had no other choice." But there is no trace of the noble Dane in her. Instead, she is serially adamant that a) she did it to protect herself (the basest of motivations!), b) for Monica ("Thanks a lot," Monica replies), and finally c) for the country. Thanks. As for her insistence that we are no different from her, I hear America demurring, Walt Whitman might say.
In the case, say, of David Kaczynski, brother of Unabomber Ted, one could in a palpable Clintonian way, feel the pain he went through during the Gethsemane leading up to his telling the FBI, "He ain't heavy, he's my brother." Here one saw a soul in agony, even though there could never be one second's honest debate as to the merits of what he was doing. (Note that in the recent newspaper story in which Ted, demanding a new trial on the grounds that he is not, after all, crazy, called his brother "Judas." It was encouraging that he added, "I do not intend by this any comparison of myself to Jesus Christ." Thanks for clearing up our confusion.) David's torment, and his subsequent donating the reward money to his brother's victims, completed the purity--might Emerson have called it the transparency? You can tell I'm no philosophy major--of his act of fraternal betrayal.
You ask what it is that makes our public life so inhospitable to loyalty. At the risk of glibness, I'd venture: money, at least for starters. That and the celebrity imperative. Joe DiMaggio, may he rest in peace, never wrote a book about his nine-month marriage to Marilyn Monroe; never said a word. Instead, he sent flowers to her grave three times a week for 20 years, and they'd been long divorced when she died. Had Barbara Walters and the whole modern media apparatus been around in 1954, would he have been permitted that silence and dignity? "All right, we'll give you an advance of six million."
Thomas Merton, monk of Gethsemane Abbey, the most famous American religious figure of the 20th century (after Richard Gere), apparently had an affair with a woman while he was a monk. She still lives. She is married. Her name is known to the press. And she refuses to talk, or have a hack British writer ghostwrite for her. Where, as James Michener once asked in a different context, do we find such people?
These examples are from a different age. In the tell-all, buy-all, sell-all culture that we inhabit, where absolution and closure are offered not in private but on prime-time television, where 48 million people tune in to watch a giggling, weeping girl discuss her betrayal by the president of the United States, surely the ultimate loyalty is to--oneself. Alas.