Self-described “billionaire tyrant” Rupert Murdoch—Australia’s most questionable export since Crocodile Dundee—is back in the limelight as the temporary new head of Fox News after chairman and founding CEO Roger Ailes abruptly resigned last week following sexual harassment allegations. With the US election only four months away, America is about to get a first-hand experience of the formidable skills in media manipulation and political demagoguery that Murdoch perfected in his home country for decades.

Ailes was the driving force behind Fox’s success for nearly 20 years. A longtime political strategist credited with the TV campaigns that won Richard Nixon and George H W Bush the presidency, Ailes was the perfect choice to head a young network aiming not to contribute to national political debate, but to dominate it.

His departure has therefore raised questions about whether the network’s glory days are behind it. Fox’s long-assumed dominance over the Republican Party and the broader American right has looked increasingly shaky with the rise of Donald Trump, and the channel’s rapidly aging audience is leaving them vulnerable to losing advertising dollars as brands look to reach a younger demographic.

But with Murdoch back in charge (at least for now), Fox now has the one person more formidable than Ailes at the helm. After all, it was Murdoch who first saw the potential for a news channel based on combative, strident conservatism in the first place. In American media, Murdoch is the all-star on the field. But in Australia, he runs the team, chooses the players, hires the coach, and owns the billboards and the stadium—and he might be about to secure the TV channel showing the game as well.

Before Murdoch took control of airwaves across the Pacific, he cut his teeth in Australia, where he was born in 1931 and lived until his mid-40s. He stills wields incredible power in his country of birth, and Australia’s political and business elite is even more in thrall to him than the Republican Party is in the US.

Murdoch began his journey toward becoming the world’s foremost media tycoon in the copyrooms of his father’s small Adelaide newspapers in the 1950s. After inheriting the family business at the age of 21, he aggressively expanded by snapping up tiny, loss-making regional and suburban papers and launching circulation wars with his larger rivals. In 1964 he purchased valuable political capital by launching The Australian, which to this day is the country’s only broadsheet publication with a nationwide focus—and the paper of choice for political powerbrokers and business leaders. Over the next few decades he also expanded into pay TV record labels, which became a sort of test run for the expansionist strategy he would later successfully apply to such efforts in the UK and the US.

Fast forward to 2016, and the sheer vastness of Murdoch’s Australian empire makes his holdings in the US and Britain look positively anemic. Australia has one of the most concentrated media industries in the world; even America’s rapidly homogenizing media landscape is a thriving ecosystem when compared to Australia.

Part of that has to do with size. Australia has fewer than 25 million people, and there’s only so many media outlets a market that small can support. But Murdoch is by far the biggest beneficiary of that dynamic: Murdoch’s News Corp owns eight of Australia’s 12 major print newspapers and their digital equivalents, which equals around 65% of readership circulation nationwide—almost three times larger than its nearest competitor. Just last month the Murdoch-owned News Corp snapped up dozens more regional community newspapers and news websites.

Murdoch used Australia as the playing ground to perfect the art of using his media properties to pressure politicians and shift public debate, making and breaking governments for more than 40 years. For example, in 1975 Murdoch infamously ordered his newspaper editors to undermine left-wing prime minister Gough Whitlam with the directive “Kill Whitlam.” That familiar bluntness had another run in 2013, when his empire launched a massive campaign urging voters to punish the then-Labor government of Kevin Rudd.

And it’s not just the politicians. There’s a correlation between the influence of the Murdoch press and a disproportionate level of climate skepticism in English-speaking countries. From Donald Trump to Brexit to the recent resurgence of Australian politician Pauline Hanson’s far-right political movement, the bombastic, xenophobic brand of populism that Murdoch has nurtured is now being read, watched, and heard all over the English-speaking world.

In Australia, Murdoch’s local bevy of high-profile conservative commentators—mirror images of Fox personalities like Bill O’Reilly, Glenn Beck and Sean Hannity—fill headlines and airwaves with constant railings against political correctness, left-wing elites, and so-called climate change “warmism” that come straight from the Fox News playbook. Even now, half a world away and with his Australian citizenship expired for more than 30 years, Murdoch’s poorly worded thought bubbles about Australian goings-on still spark furious reactions.

If that weren’t enough, Murdoch is set to extend his dominance of the Australian media landscape even further over the next few years. The newly elected Liberal government has plans to severely water down decades-old media ownership laws aimed at preventing one player from controlling too much publishing real estate. If this passes, it could be a potentially catastrophic development in a country so severely lacking in media diversity. The consequences of an increasingly monopolized media space will leave Australian political discourse even more vulnerable to Murdoch’s octopus-like reach.

Under the current rules, a single person or company is prohibited from controlling more than two of three platforms (TV, print, and radio) in a radio license area, such as a major city. As he already has a stronghold in print and radio, those laws have largely prevented Murdoch from expanding into free-to-air television. That restriction is now being scrapped, which allows Murdoch to muscle in on a platform he’s been historically shut out from and assert even more domination over major cities like Brisbane, Adelaide, and Hobart, where his newspapers already lack any effective competition. It’s frightening to think how complete Murdoch’s influence might become in Australia if he can successfully purchase a controlling share in one of Australia’s three commercial free-to-air TV stations. (And yes, there are only three commercial free-to-air TV stations in Australia.)

The US isn’t at that stage yet, but it’s not that far behind either. While the Federal Communications Commission (FCC) recently recommended keeping existing media cross-ownership restrictions largely intact, much of the damage is already done: 90% of American media is owned by just six companies, one of which is Fox. The worldwide trend toward mass media consolidation has its roots in the all-consuming nature of News Corp, the beast that Murdoch created in Australia more than 50 years ago.

One of the most concerning side effects of Murdoch’s ongoing monopolization goes much further than any political agenda. As media diversity in Australia has declined, so too has trust in news and the political system itself. This makes Australia something of a canary in the coal mine: Only a lowly 39% of Australians ”think you can trust most of the news most of the time,” whereas 60% of Americans say they have little or no trust in the mass media to report accurately and fairly, and an astonishing 81% of Americans express distrust in government.

That’s something to ponder while Fox News hunts for its new permanent chief: If you think Murdoch’s hold on American politics is too powerful as things stand, then imagine if Fox was the only game in town.