In a rare post-presidency speech, delivered before the Montreal Chamber of Commerce, Obama called on people, in the face of uncertainty, to stand by some of the very post-World War II economic and political institutions Trump has repeatedly called into question.
"In periods like this, people looking for control and certainty -- it's inevitable," Obama told the Canadian audience. "But it is important to remember that the world has gone through similar moments. ... Our history also shows there is a better way."
He said people should overcome fear and not listen to those who "call for isolation or nationalism" and those who "suggest rolling back the rights of others."
Obama's comments set a different tone than Trump, who campaigned on an "America First" message and has called Americanism his "credo."
"We're also bound by the institutions that we built to keep the peace," Obama said, referring to the UN, NATO and NAFTA.
Obama said that everyday people who felt left behind by government and a changing world could find authoritarians alluring. He said people who felt at a loss with the democratic process could "try anything," but that liberal values would win out over time.
"I am convinced that the future does not belong to strongmen," Obama said.
Without mentioning Trump, Obama spoke about the importance of wealthy nations investing in development abroad.
"We're going to have to summon the same capacity to adapt to new circumstances that we saw after World War II," Obama said. "We're going to have to replace fear with hope. That's the spirit that we need right now."
Obama repeatedly touched on the threat of climate change and Trump's decision last week to initiate the US' withdrawal from the Paris climate agreement.
"Obviously, I'm disappointed," Obama said.
Still, he tried to make the case that the agreement could be effective, regardless of Trump's decision, calling the accords "an agreement that even with the temporary absence of American leadership, will still give our children a fighting chance."
He commended state and local leaders who have pledged to push for clean energy and combat climate change.
"They will keep pushing forward for the sake of future generations," Obama said.
Since leaving office, Obama and his wife Michelle spent a significant amount of time off-radar and out of country.
He emerged in April
to speak at a form in Chicago. He has spoken several times since then.
At the Montreal event, just as he made a case for the post-World War II international order and his own legacy, Obama argued for increased civic engagement and the spread of democratic values. He said low-civic engagement and a lack of belief in the average person's ability to affect change in government weaken democratic institutions and are responsible for the advance of "reactionary" politicians.
Obama pledged to work on increasing democratic participation for the rest of his post-presidential life.
"The focus for the rest of my time on this Earth -- in addition to enjoying my children and, in a distant future, grandchildren -- will be active citizenship in the United States and around the world," Obama said.
Canadian Prime Minister Justin Trudeau tweeted Tuesday evening that he met with Obama in Montreal.