Harper can either take major, collaborative action to erase the deep and lingering effects of a school system that separated 150,000 kids from their families, Atleo said, or he can persist in chipping away at policy with small, unilateral measures and making grandiose promises that amount to little else besides more procedures.
"We're faced with a real moment of reckoning here," Atleo said in an interview on the fourth anniversary of the apology.
"The rate and pace of change is too slow."
On June 11, 2008, Harper stood in the House of Commons and delivered an emotional, historic speech that took full responsibility for government attempts to assimilate aboriginal children, causing great harm that has lasted for generations.
"There is no place in Canada for the attitudes that inspired the Indian residential schools system to ever prevail again," Harper said.
"You have been working on recovering from this experience for a long time, and in a very real sense we are now joining you on this journey."
To commemorate the fourth anniversary, Aboriginal Affairs Minister John Duncan unveiled a stained-glass window by Metis artist Christi Belcourt that will eventually be installed in the House of Commons.
"I think its symbolism is just fine. What's really required is action. Real change," said Atleo, warning that the First Nations community's patience with discussions about poverty, housing, resource-sharing and education is wearing thin.
Atleo is campaigning for a second term as national chief of the Assembly of First Nations in a race where his critics say he has not been tough enough on the Harper government.
He said the government can't afford to alienate a major source of labour that lives on top of Canada's ample natural resources at a time when Ottawa has made resource extraction a top priority.
Duncan, however, says history cannot be undone overnight.
"You have to take a step back," he said in an interview. "We, I think, have many things to celebrate."
Duncan pointed to compensation for former residential school students, the ongoing Truth and Reconciliation Commission, which encourages healing among survivors, as well as increased funding for child welfare and education.
"I've talked to many, many people for whom the apology was life-changing. It's pulled many families together," Duncan said.
"Of course, it hasn't fixed everything. This was a terrible chapter in Canadian history."
Harper's apology acknowledged that the long-term effect of having generations of families pass through residential schools is that today's families often lack crucial parenting skills.
"We undermined the ability of many to adequately parent their own children and sowed the seeds for generations to follow, and we apologize for having done this," Harper said.
But at the same time, the federal government is fighting in court to quash demands from First Nations organizations to fund aboriginal child welfare at the same level as provincial governments.
On education, demands that First Nations schooling be funded at the same level as provincial schools have been met with process — a task force that led to a report that led to some initial funding and promises for legislation down the road.
Indeed, crowds of First Nations school children marched in the street near Parliament Hill on Monday and in smaller groups across the country, demanding equal funding for education and telling Harper he should not need to apologize twice.
"Saying you're sorry has to include taking real action to close the gap. And that has not happened," said NDP critic Jean Crowder, who was part of the Ottawa march.
But the artist whose stained glass work was the government's focus of the day begged the public not to be too cynical about the hard work needed to repair the relationship between aboriginal people and the rest of Canada.
"There will be people who will say, 'What will a glass do when there are so many issues left to deal with?'" Belcourt said during the unveiling of the design of her artwork.
She estimated some 60,000 tourists a year would see the work in the House of Commons, and predicted it would serve as a constant reminder to politicians and the media of the collaboration that still needs to take place.
"Reconciliation is not just one-sided. Reconciliation is the two sides coming together," she said. "So I would just like to ask Canadians to please consider this."