British Prime Minister David Cameron's profound apology for the killing of 14 Northern Ireland protesters on a day infamously known as "Bloody Sunday" was a rare, wondrous event. Nearly 40 years after an official whitewash account of that dark day in Londonderry, a detailed report cleared those who died. They were unarmed, peaceful protesters, fired upon in a way that was "unjustified and unjustifiable," Cameron said with undeniable sincerity.

The moment cleansed a national soul.

We need more of them.

Apologies are tricky. If they are done because someone is found out -- say, in the fashion of Sarah Ferguson or South Carolina Gov. Mark Sanford -- they can sound forced and convenient, like the wrongdoer is just sorry for having been caught.

The apology by BP executive Lamar McKay before Congress was the worst kind. The man's careful parsing of words and proud mien made his "sorry" for the ruin his company is causing sound grudging and even a bit contemptuous, though the BP apology train picked up as the week went on.

But there is also transcendence in a national apology when it is heartfelt and due. Putting right a historical wrong by acknowledging how an act of volition was a devastating misstep is a grown-up view of reality, and a close cousin to humility -- something every great nation should have in spades.

President Barack Obama has been mocked by those on the political right for being our "apologist-in-chief." Last year, the Heritage Foundation published an online list of his "Top Ten Apologies" to date. The blogger denounced Obama's "mea culpa campaign" and the way the president would often concede American mistakes to international audiences, whether that be the establishment of Guantanamo or how the U.S. in the past "sought to dictate" policy to Latin American nations.

Obama's willingness to truthfully analyze the negative aspects of America's fingerprints has infuriated the tea baggers. This blinkered group sees America as a myth rather than a complex society run by a succession of leaders with foibles and limited foresight.

Meanwhile, Obama's small admissions have set a new tone in foreign policy and moved much of the world to have a better opinion of our nation. In a recent annual BBC World Service poll, positive views of the U.S. rose 21 percent in Germany, 18 percent in Russia, 14 percent in Portugal and 13 percent in Chile.

What is it about people on the right wing and their aversion to apologizing? Every nation makes mistakes, and those errors become clearer in hindsight. Even Ronald Reagan apologized to the victims of the Japanese internment during World War II. The legislation he signed "to right a grave wrong" stated flatly that act of putting 120,000 mostly Japanese-Americans in interment camps was based on "racial prejudice, war hysteria, and a failure of political leadership."

This kind of apology is not a demonstration of weakness. It is a mark of self-confident judgment and sober reflection. It means a nation is willing to live up to its purported values, acknowledge when it falls short, and accept honest criticism.

And by that yardstick Obama has done far too little apologizing.

We still need to apologize to the hundreds of Arab and Muslim noncitizens swept into U.S. detention facilities following 9/11 who had nothing to do with terrorism. Many were seriously mistreated in detention, as if they were Osama bin Laden himself.

Also on the list are the hundreds, possibly thousands, of other innocent victims of the war on terrorism who never sought to do America harm but were tortured, abused or thrown into indefinite overseas detention by the U.S. due to their religion or nationality. They are our generation's Japanese internees and Londonderry Catholics.

But an apology for these people isn't forthcoming. It took the Senate until last year to finally apologize for our national crime of slavery. It may take that long before innocent rendition victims such as Canadian Maher Arar and German Khaled El-Masri get theirs. With our country's right wing standing in the way, America will have a long wait for that cleansing "we're sorry" to occur.

Available at Amazon.com:

Were You Born on the Wrong Continent?: How the European Model Can Help You Get a Life

The Disappearing Center: Engaged Citizens, Polarization, and American Democracy

The Virtues of Mendacity: On Lying in Politics

Bush on the Home Front: Domestic Policy Triumphs and Setbacks

The Political Fix: Changing the Game of American Democracy, from the Grassroots to the White House

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