Don't do it, Canada.

That's the essence of the blunt warning from Susan Rice, the U.S. national security advisor under U.S. president Barack Obama and the former U.S. ambassador to the United Nations. This is a woman who was involved in the most precarious of security issues involving the United States — and when she talks about this issue, she leans in and is firm.

Rice is clear about how dangerous she considers the risk of allowing Chinese tech giant Huawei to work on 5G networks in Canada.

"It's hard for me to emphasize adequately without getting into classified terrain how serious it is," she said in an interview with The National this past weekend in Washington.

It was a conversation about her memoir, Tough Love, about the current turmoil in the U.S. and about her own political aspirations too. But it was the discussion about China and Canada, and the prospect of Huawei's place in Canada's 5G projects, where Rice seemed the most concerned.

"It gives the Chinese the ability, if they choose to use it, to access all kinds of information. Civilian intelligence, military, that could be very, very compromising," she said. "So as much as I disagree with the Trump administration on a number of things, on this I believe they are right."

Susan Rice warned that allowing Huawei to work on 5G networks in Canada 'gives the Chinese the ability, if they choose to use it, to access all kinds of information.' (Chip Somodevilla/Getty Images)

The U.S. government blacklisted Huawei in May, deeming it a national security risk, meaning U.S. firms aren't allowed to sell the company's technology without government approval. Canada has yet to make its call, but Rice insists the U.S. decision isn't one Canada can ignore.

Especially tricky, she maintains, is Canada's key position in the Five Eyes intelligence-sharing group that also includes the U.S., U.K., Australia and New Zealand. Her suspicion is that should Canada open the doors further to Huawei, it risks being cut out of shared information from the Five Eyes.

"That will throw the Five Eyes collaboration, which serves the security interests of every Canadian and every American, into jeopardy. It just can't be done," Rice said. "I don't see how we can share in the way we have.

"It's not a joke. It's truly serious."

Empathetic as she is to the current tensions between Canada and China, Rice thinks the U.S. was right to ask Canada to arrest Huawei chief financial officer Meng Wanzhou in Vancouver last year.

Watch Rice discuss why she thinks Canada was right to arrest Meng:

Former U.S. national security adviser and ambassador to the UN Susan Rice says Canada should not back down to China over Meng Wanzhou's arrest. 2:29

"What worries me, though, is then the way President [Donald] Trump suggested, having asked for the arrest, that, you know, we might trade her at your expense. You know, in the context of ... some trade negotiation, if it were beneficial in his estimation to get what we want in the trade deal," she said. "That's not right."

Countdown to U.S. presidential election

This conversation with Rice took place a year before Americans go to the polls in the 2020 presidential election — and she has some thoughts on that, too.

"I think the Democrats are likely to win," Rice said. "I can't be certain of that.... But I think that the American people have seen a lot of Donald Trump now and much of the downside of his leadership, which is rife with dishonesty, rife with self-interest domestically and in terms of foreign policy."

Rice, left, shakes hands with Chinese President Xi Jinping, second from right, in 2014. (Kim Kyung-Hoon/AFP via Getty Images)

Rice also acknowledged that while she did not initially favour the idea of an impeachment inquiry, she's come around. To see the transcript of the president's phone call with Ukrainian President Volodymyr Zelensky was to demonstrate, she says, "the absolute clarity that it seems to demonstrate about the president's interests in extorting dirt on a political rival, false dirt on a political rival for his own personal gain and to hold up congressionally approved military assistance to a country that needs it desperately because of Russian aggression."

"It's so outrageous, it's such an abuse of power that ... to fail to pursue an inquiry would basically be to preside over the separation of powers and tacitly bless lawlessness out of the White House."

Rice spoke freely too about a phenomenon many Americans and Canadians will recognize: the stress of increased polarization even within families. She understands that terrible tension when people who love each other disagree so vehemently about politics that talking becomes hard.

It's happened with her own son, Jake. He is a staunch conservative and she said she's not complacent about how stark their differences are and how threatening that can be to the relationship.

Rice, right, served as U.S. national security adviser as well as ambassador to the United Nations under U.S. President Barack Obama. (Pete Souza/The White House)

This is something she insists many in the U.S., including herself, need to work on with love.

"I will refuse to bet against America's ability to grow and renew itself to heal," Rice said. "And so yes, this is a difficult time. Is it the most difficult time? No way. Can we do it? Yes"

Her focus on the future, not strictly where she's been, says a lot about Rice's ambitions. Is she prepared to run for office in the future? It seems so.

"I've thought about the [U.S.] Senate. I've thought about, frankly, other kinds of offices, higher and lower depending," she said.

And yes, current Democratic hopefuls have reached out to her for advice. Is she prepared to endorse someone just yet? No.

Is there a chance she would be named on a ticket as vice-president? "I can't imagine that," she said — but it's not a no.

Watch Rice discuss her connection to Canada and late CBC journalist Barbara Frum: