Longtime readers will know that one of my heroes is Spiro T. Agnew. On the day he resigned the vice presidency and pleaded no contest to a tax- evasion charge, he had a full and heavy dinner at an Italian restaurant in Baltimore. I admire a man who has an appetite after such a rotten day.

Now my admiration has turned to Agnew's former boss, Richard Nixon. Like Agnew, nothing seems to stop him. Dwight Eisenhower humiliated him, and Nixon came up smiling. He lost the governorship of California, told the press it would not have you- know-who to kick around anymore and, as usual, reneged on his word. He ran for the presidency and won, only to have to resign during Watergate. You remember Watergate?

It seems, though, that Richard Nixon does not. Neither disgrace nor defeat can keep this man down, and just about every spring since 1946, he has resurfaced to announce, yippee, that he is back.

Now the man who presided over the loss of Vietnam, who won a Reagan- like landslide against George McGovern, has published a book saying that it was the press and Congress that lost Vietnam for us. Richard Milhous Nixon had nothing to do with it. There is epic gall to this but, worse yet, a message.

Richard Nixon is, if anything, a master of timing. Like Houdini, he knows just when to appear. This, he senses, is once again his springtime, when America will once again be receptive to his message. He is telling us that Vietnam was lost because a fifth column called politicians and the press gave it away. Don't apply the lesson of Vietnam to Central America, he says. The thing could have been won.

Wrong -- or, if right, at what cost? But aside from that, Nixon's argument is morally repulsive. Just as he seems not to appreciate that he resigned in digrace and should not be heard from again, he also does not want to acknowledge that fully half of the American deaths in Vietnam occurred after he took office in 1969. That is to say that after the war was, in effect, over -- after Tet and the onset of peace negotiations -- more than 25,000 Americans lost their lives. And almost no one can say why. Nixon may have his reasons, but no one should have to give his life for a purpose not immediately apparent and and not even remembered a decade later.

Even so, this is a purely ethnocentric view of history. It looks at things from just the American view, and that's not right. The Vietnam War also affected Vietnamese, Laotians and, of course, Cambodians. Countless numbers of them died after Richard Nixon took office, some of them in the so- called secret bombings that were, for sure, no secret to them. Anyone who has seen the film,"The Killing Fields," would realize -- regardless of politics -- that the war in Cambodia was something more than an adjunct to the fighting in Vietnam and, certainly, more than just a story on the nightly news.

Wondering how Agnew could have gorged after resigning from office is a minor mystery compared to Richard Nixon's ability to shed disgrace and failure and continue on his morally obtuse way. It sometimes becomes necessary for a nation to fight, but to fight for nothing is not war but tragic farce. Lyndon Johnson, at least, had a vague, if cockeyed, idea of why he wanted to fight in Vietnam -- dominoes and all of that. Nixon, though, had nothing -- nothing but image and prestige and some grand Kissingerian view of world power for which others should die. Richard Nixon has become the political equivalent of a bad accident: you simply cannot keep your eyes off him. Maybe for that reason, he writes essays for magazines, offering wisdom any staff writer could provide for at least half the price. From time to time a book issues forth, and now we have a new one. The lesson of Vietnam, he says, is not that we were wrong in attempting it, but in failing.

No. Beg your pardon, sir, but even if we had won, we would have been wrong -- and we would probably still be fighting.

If you wish, you may plunk down $14.95 for the latest Nixon book or wait for the one that explains how Watergate was someone else's fault. Or you can, for free, go to the Vietnam War Memorial and count the names. That takes the strongest stomach of all.