Jacinda Ardern, who now calls Sydney home, has delivered a message to Australian politicians from the stage of the city’s Opera House.

Politicians, the former New Zealand prime minister turned academic told the audience on Sunday, were exacerbating the problem of polarisation within society and needed to be better.

“We have a responsibility not to engage in binary thinking, not to engage in the language of violence, [but] to rebuild trust by building financial security in a time of deep insecurity,” Ardern said during a forum with the author Anna Funder.

“There are things we could be doing but, right now, we’re making it worse, not better.”

In the past few decades, people across the world felt an increasing sense of insecurity as globalisation took hold, and they began attacking institutions like the World Trade Organization, Ardern said.

Politicians offered proposals such as Brexit in response to the insecurity – saying “Here’s what you blame” – which then paved the way for the rise of leaders like…