One consequence of Donald Trump's presidency is that the violation of norms, the breaks with tradition, and the pointless petty feuds tend to blur into a single mess that we call "the news" and that most people try to ignore if they don't want to spoil their good mood.

But as Trump's ambitious, amorphous domestic agenda stalls thanks to incompetence and the slowness of Congress, it's important to remember that when it comes to foreign policy—an area where presidents normally have a great deal of freedom—he has already made big waves.

Right after getting into office he scuttled the Trans-Pacific Partnership, a free trade agreement he campaigned against. His budget includes major cuts to UN funding. During his first trip overseas, Trump conspicuously did not signal his support for the mutual defense pact underlying NATO and alienated America's traditional allies; a few days later, he announced that the US would withdraw from the Paris climate change agreement. (Trump later confirmed he backed NATO's mutual defense provision.) On Friday, it was reported that Trump wants to impose new tariffs on steel against the advice of most of his cabinet.

Many of these actions are symbolic, but taken together they represent a major shift in the United States' posture toward the world. In the aftermath of World War II, America emerged a global superpower and helped create international institutions like the UN and the World Bank. Presidents from both parties worked to increase global free trade, and the American military intervened in conflicts all over the world, first to slow the spread of communism and then, after the collapse of the Soviet Union, for humanitarian reasons. In many cases, these policies caused misery and unnecessary death, but whatever the virtues of the US's domination of the world its status as a global superpower was unchallenged.

Trump is changing that. He is causing rifts between the US and its traditional allies, his protectionism could alter the flow of world trade, and fewer countries are looking to the US as a source of bedrock security.

The potential effects of this new era in foreign policy are detailed in a report out last week from the Economist Intelligence Unit called "The US Is Abdicating Its Global Leadership." I called Mike Jakemen, a global economist at the EIU, to unpack the consequences of Trump's America-first radicalism.

VICE: What could some of the tangible effects of Trump's moves so far be?
Mike Jakemen: Some of the tangible effects of the US coming out of the Paris Agreement could be, for example, the US losing some competitiveness in developing renewable technology. Suddenly the US federal government is going to be a smaller purchaser of that kind of stuff. Before that there would have been lots and lots of companies eager to sell to the federal government; they're going to be looking for other opportunities.

In terms of taking the US out of TPP, that has now enabled the renegotiation of NAFTA to begin, because you couldn't have the US signing up to the TPP, which builds on NAFTA, and simultaneously trying to negotiate NAFTA.

And I think the tangible consequence of Trump failing to confirm this mutual defense clause was directly behind the comments that [German Chancellor] Angela Merkal made a day or so later about Germany not being able to rely on some of its traditional allies. She meant the US and the UK, but the US was the bigger one. And Canadian Foreign Minister Chrystia Freeland said that Canada doesn't feel like it can be protected by the US's security umbrella any longer and has to go out and make its own arrangements. Which is a big statement, given how overwhelmingly dominant the US is as a trade and security partner for Canada.

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One surprising part of the EIU report to me was the idea that Australia might move closer to China. What's the deal with that?
The biggest question in Australian foreign policy for the past 30 years is that it's got this emerging superpower (China) in its back yard, but on the other hand it's got this long-held security alliance with the US. So what does it do? At the moment Australia is trying to maintain security ties to the US but also it's reorienting its economy toward servicing China's demand for commodities, education, and tourism. So it's trying to have the best of both worlds.

Of course, if the US becomes a less reliable security partner, they might start to think, Hold on, if we're sacrificing some leverage with China in order to maintain this relationship with the US, but we don't think the security relationship is as tight or as worthwhile as it used to be, then perhaps we'll revisit that.

If the US isn't going to lead in clean energy, say, or trade agreements, presumably they'll be some slack to pick up. Will China benefit from this?
Certainly, if the US is a less visible presence in Asia, then China is the country you'd primarily look to fill that gap. It'll be interesting to see how aggressively China pursues island-building in the South China Sea, which the US opposes and several US-aligned countries in Asia also oppose.

Another country to watch out for is Russia, which wants to be a bigger force in the Middle East. Obviously appetite in the US for participating in Middle Eastern conflicts is very low, so I think Russia feels there is an opportunity there.

I feel a little bit like geopolitics, having been stable-ish since the collapse of the Soviet Union, is a bit like a snowglobe that someone is starting to shake. The next three or three and a half years of the Trump administration will give us an idea of where things will settle again.

Despite Trump withdrawing from the global order somewhat, he seems very ready to resort to military action, as he did when he launched a strike against a Syrian airbase. Does that worry you at all?
I don't think we should forget how militarily active the US has been throughout the Obama administration. Let's not assume that this has been a very peaceful country that is starting to fire off rockets at will.

But the thing that worries me, and the big difference between Obama and Trump, is we know the agony Obama went through before calling for military action. We know that those were decisions that were not taken lightly. Whereas with Trump, the airstrike on the Syrian airbase—I think it's quite clear that there was no broader strategy beyond, This is wrong. I'm going to do something about it. Here's the button I'm going to press to do it.

Some people who support Trump are probably thinking that a lack of global engagement isn't a bad thing, that we should focus more on domestic issues. Do you think Trump's anti-globalist attitudes will end up hurting America in some way?
If you impose tariffs on Chinese imports, the US isn't necessarily able to manufacture the same goods or produce the same raw materials at the same cost. That means the cost of the materials goes up, which means the cost of living for ordinary Americans goes up. There's a reason the US is importing from China, which is that it's more cost-effective to do it that way. For lots of sections of American society—though not all of them—globalization has been beneficial, because the cost of cars and the cost of food and all sorts of consumer goods has fallen hugely. If Trump starts messing with that balance, Americans will suffer.

He risks a big deterioration in economic relations with China, and China is now more important than any other country in global supply chains. I think Trump is mistaken if he thinks he can bully China and not suffer consequences in return.

Follow Harry Cheadle on Twitter.