Justin Trudeau, speaking in that earnest cadence of his, rose in the Commons Wednesday and, speaking on behalf of all Canadians, apologized for an event no living Canadian had anything to do with.

Further, he directed the apology to people who were not alive at the time it happened (more than a century ago), most of whom, in all likelihood, never met the ancestors who received the shabby treatment for which Trudeau is now officially sorry.

That isn't to say he shouldn't have apologized.

People in British Columbia's South Asian community wanted an official apology for the rejection of 376 migrants, mostly Sikhs, who arrived in Canada aboard the Komagata Maru 102 years ago, and they presumably feel better now, having obtained it.

The apology didn't cost anyone anything, after all, and has no effect on any government policy. It was just a nice thing to do.

Particularly so because the British, who were in charge of India in 1914 and whose police shot and killed 19 of the Komagata Maru's passengers during a riot after Canada sent them back, have not apologized, and don't seem to have any intention of doing so.

Most of the 376 passengers from India who travelled on the Komagata Maru to Vancouver were denied entry into the country and sent back to India. (Simon Fraser University Public Affairs and Media Relations)

Which should be no surprise.

To quote historian Hugh Johnston, who wrote a book on the Komagata Maru incident, if the British began apologizing for all the sins of the empire, "they would be apologizing from the moment they got up in the morning to the moment they went to sleep at night."

Actually, the British colonial authorities committed atrocities that utterly eclipsed the killings of the Sikhs from the Komagata Maru, which Johnston says happened after some of the ex-passengers shot and killed a police commander who made the mistake of wading into the crowd when someone snatched his baton.

The most famous was the Amritsar massacre of 1919, in which a British colonel, enforcing a curfew in the Indian city, ordered his troops to expend all their ammunition on unarmed pilgrims in an enclosed area, killing hundreds of innocent people and wounding a thousand or so more.

"The British fired people out of cannon," says Johnston. "I don't think they've apologized for that."

But then, even when the British do say "I'm sorry," they use it most often as a question, and rather archly at that.

Americans hardly use the phrase at all, especially officially.

President Barack Obama, when he visits Hiroshima later this month, will no doubt sympathize, but not apologize, for what can be objectively described as the greatest single act of war criminality in history – deliberately targeting civilians is the essence of a war crime, and dropping a nuclear bomb on a city certainly qualifies, especially when you do it again a few days later.

In this Aug. 8, 1945, file photo, the shell of a building stands amid acres of rubble in this view of the Japanese city of Hiroshima. The U.S. has never apologized for dropping an atomic bomb on the city during the Second World War. (Mitsugi Kishida/Associated Press)

That the bombing shortened the war and saved American lives is as may be; it doesn't change the deliberate obliteration of hundreds of thousands of civilians at a stroke.

And there's been no apology for invading Iraq on a false pretext, triggering bloody chaos and death on an industrial scale.

Prime Minister Stephen Harper greets Chinese head tax survivor James Pon in Ottawa on June 22, 2006, during a ceremony announcing the government's official apology for the tax. (Tom Hanson/Canadian Press) Canadians, though, have a different history. They tend to say I'm sorry constantly, which is perhaps why there have been so many official apologies from Ottawa.

Canada has apologized to Chinese Canadians for a head tax first introduced in the 19th century, to Japanese Canadians for having locked them up in internment camps during the Second World War and confiscated their property, to Indigenous Canadians for the suffering they endured in the residential school system, and to the Inuit of Inukjuak, who were relocated from northern Quebec to Ellesmere Island in the name of protecting Arctic sovereignty in the 1950s, and left to fend for themselves without adequate supplies not far from the North Pole, in one of the harshest environments on Earth.

"Those were people under the direct care of the government of Canada. It was devastating," says Johnston. "The Komagata Maru was a much lesser incident. I don't think the arrival of hundreds of passengers who had decided to voluntarily challenge Canadian immigration policy is comparable."

Yes, that immigration policy was racist, but most immigration policy is arguably racist, even today.

(Notably, Canada has not officially apologized for turning away another ship, the MS St. Louis, in 1939. The 907 European Jews aboard, desperately fleeing Hitler, were eventually forced to return to Europe after several other countries barred them, and 254 of them were eventually murdered in the Holocaust.)

In 2008, Prime Minister Stephen Harper stood in the House of Commons to officially apologize to former students of Canada's native residential schools. (Reuters/Library and Archives Canada)

All that said, Johnston says historians have not really decided how significant official apologies are in any event.

They are a relatively recent phenomenon; Justin Trudeau's father, for example, was not an apologizer. Pierre Trudeau believed the past could not be rewritten, and preferred to take responsibility for contemporary policies, rather than the actions of deceased generations.

Trudeau pere was also keenly aware of opening the door to financial claims.

There won't be any compensation in the case of the Komagata Maru – as Justin Trudeau pointed out Wednesday, Canada was in any event not solely to blame for what happened – but when his government offers a sweeping apology, as it plans, to gays whose lives were ruined by the blanket ban on their participation in the public service and the RCMP witch hunts carried out against them just a generation or two ago that will be a different matter.

A good number of those people are still alive, and their suffering is measurable. That apology will almost certainly come with a bill.