Bestselling author Louise Penny feared she had gone too far when writing about a plot to add Canada to the United States of America. This was 18 months before Donald Trump was elected for his second term as US President and sparked a trade war with America’s closest ally. In her prescient 20th Chief Inspector Armand Gamache thriller, The Black Wolf, which is out now, powerful forces on both sides of the border conspire to threaten Canada’s future as an independent nation.

Louise says: “This was written 18 months ago, before Donald Trump was elected for a second time, but the issue is there are elements (in my book) that want Canada to become the 51st State. I was afraid when I wrote it that I had taken it too far, that people simply wouldn’t follow me there, that it was unbelievable. As it turns out, I may not have gone far enough!”

She adds: “There are also some pivotal scenes in The Black Wolf that are set in The Haskell Library, a free library and opera house, which actually exists. “It’s a little village library and opera house, an oddity, that sits right on the border of the US and Canada, between Vermont and Quebec. There is a dotted line through it where the border does actually exist.

“So there are some scenes set there and then it became a flashpoint for the Trump administration, because they decided they would close this library to Canadians, which was such a petty thing to do. Who attacks libraries? Well, I’ll tell you … petty despots attack libraries, a little village library that is symbolic of the friendship and the sacrifices that both countries have made for each other.

“If I had been writing this book now I never would have gone there because it would have felt like I was ripping off a quite frightening political situation, certainly within Canada but also within the US.”

Her latest novel is the companion piece to previous thriller The Grey Wolf, which was published last November and became a New York Times bestseller. This led to an invitation to launch the second part of the story, The Black Wolf, at The Kennedy Center in Washington DC, which Louise, 67, was “thrilled” about.

She says: “Never in my wildest dreams did I think I would be invited to The Kennedy Center. It would have been incredibly meaningful, a real watermark for me. And so I said yes, of course. And then there was what amounted to a coup at the Center, getting rid of half of the board, all Democrats including the chairman of the board who had single-handedly kept it alive.

“So he (Trump) wiped them out, put himself in there and ultimately installed his own people – so there was no way I could go there.”

Louise adds: “I wish I could say it was a difficult decision but it was not. It had difficult repercussions but there was no way I could do it. So I had to say to my publisher there was no way I could tour in the US, and god bless them, despite them taking a hit from this, they absolutely agreed. I will take a hit from this but so will they.

“America is by far my biggest market but it’s important for me to make the distinction between the administration and my readers. This is not an attack on my readers, but just in support of Canada.”

The author says the sense of “outrage and hurt” in Canada when Trump first imposed crippling tariffs on them was palpable: “When Trump was elected there was concern, but I don’t think many people thought he would declare economic war on us. And there are people who believe the plan is to bring us to our knees economically.

“I don’t know where I stand on this, but it’s right to be vigilant. Six months to a year we could probably take, but four years down the line, I’m not sure. Respect for the US among Canadians is very, very low.”

She adds: “Canada is water and mineral rich, with a lot of open space. This is a lot of what countries like the US will need and what happens when they run out of these resources. It may not happen in my lifetime, but if climate change continues and the droughts continue…”

In some ways the freeze in relations between the neighbouring countries is ironic as an event in the US provided the spark for Louise to turn her long-held dream of writing a novel into reality.

She started her first Gamache thriller, Still Life, after the 9/11 terror attack, a time when the world felt like a frightening place. So she created a fictional village in Quebec called Three Pines, which had been a code for safety for loyalists crossing the border north during the American Revolution. And Louise filled it with characters she knew she would want to spend time with, including her complex but endearing lead detective Gamache.

He was based on her husband Michael Whitehead, a former head of hematology at Montreal Children’s Hospital, who she cared for as he battled dementia for three years before passing away in 2016. She says: “When I started Gamache I hoped to create a character I would not tire of, so I created a man I would marry. He is not perfect, of course he’s not perfect, but he’s easy to be with – he is a decent person.

“Three Pines is inspired by a lot of places and then the final layer was just creating a place that I would want to live in. It was conceived after 9/11 when the entire world was shocked. I think it came home to all of us that no place is safe. But we all wanted to feel safe so I wanted to create this little village where there would be a sense of safety.

“Three Pines is the code for safety, initially many hundreds of years ago for the loyalists that came across during the American Revolution.”

Her first three books were adapted into a Prime Video drama three years ago, Three Pines, with actor Alfred Molina portraying Gamache. It was not renewed for a second series, leaving Louise with mixed feelings: “I was ambivalent to the Amazon adaptation of Three Pines. It scored on a number of levels, Alfred Molina was great as Gamache, but I fought hard to get a Quebecois as the lead and they felt they needed a name.

“They did not get the sense of place, the community, the things that are the beating heart of my books. It really could have been set anywhere and that was frustrating in the extreme.” She adds: “Oddly enough I was upset when it wasn’t renewed. I felt badly for the actors and for Molina. The production company and Amazon said they all wanted it to continue, but this felt disingenuous as no one would put the money up for it.”

However, she has fonder memories of creating a scarily plausible political thriller with former secretary of state and first lady Hillary Clinton, 78. State Of Terror was released to critical acclaim in 2021 after the two friends found they had time to finally write a book together during the pandemic.

Louise says: “It worked because we both brought something different and we managed to deepen our friendship, instead of ruining it.”

Asked if they could write another book together, she says: “We were together a couple of weeks ago and talked about doing another one. We came up with an idea and then I think we both got in the pool and forgot about it. It’s hard because she is busy and I am busy, and we just don’t seem to have the time anymore, but we would love to, because we love the characters.

“Right now there is a movie adaptation under way for State Of Terror, which is a long process.”

Louise adds: “I have just signed another two-book deal for Gamache and I never tire of it. As long as I have what I consider to be fresh stories and I am still loving it, I’ll continue.”

• The Black Wolf by Louise Penny (Hodder, £20) out now