Tariffs of 25 percent that US President Donald Trump has threatened to impose on the European Union may push the bloc toward greater strategic autonomy, even if uncertainties remain on how far things will go, experts say.

"If Trump imposes the threatened 25-percent tariffs or any tariffs on Europe, which he has so far only indicated but not implemented, it will send the Europeans further down the road that they are already taking, which is, increasingly, they are talking about their own autonomy," said Radhika Desai, a professor in the Department of Political Studies at the University of Manitoba in Canada and a visiting fellow at the London School of Economics and Political Science.

"But with Trump it's hard to tell. One day he is imposing tariffs, and another day he is reversing or modifying them. Exactly how that unfolds will depend."

The specter of 25-percent tariffs on all imports to the US from the EU came into play in late February when Trump told reporters in a cabinet meeting at the White House that "we'll be announcing it very soon".

Tariffs of 25 percent on all steel and aluminum imports into the US came into effect on March 12. In response, the European Commission has said it will retaliate in two steps, targeting US exports worth up to 26 billion euros ($28 billion).

However, the first step, originally to take effect on April 1, has been delayed until mid-April, pending negotiations, the commission announced last week.

Desai described the EU countermeasures as "saber-rattling noises", saying the Europeans "must be seen" to stand up to Trump to send a message to him and European voters generally.

'Historically close'

"The question is how much (European countries) want to separate from the US. Because at the end of the day, the relations between the big capitalist classes of the US and Europe are fairly close, and they have historically been made so.

"The other question is how much they can assert their autonomy, particularly in the form in which they are saying they will do so, which is extremely belligerent, warlike. They said, 'We are going to arm ourselves' or 'We are going to spend more on European security'… The fact of the matter is that there are all sorts of logistical problems with this.

"Overall, things are going to get a lot more confusing. It's not that we're going to see a very straightforward emergence of an autonomous Europe."

Martin Jacques, a senior fellow at Tsinghua University in Beijing and Fudan University in Shanghai, said Europe is "in a quandary", having realized only belatedly what a serious impact so-called America First policies could have on the continent.

"Europe was utterly and completely unprepared for this situation. There was really no excuse for this lack of preparation. We've had Trump 1.0. We've had all the stuff coming from him in the four years since he was out of office. Trump has made his position and attitude toward Europe clear, but Europe was still living in a dreamland, really.

"The dreamland was the relationship with the US was absolutely secure and would continue. So it has never had a plan B; it only had plan A, and that was the relationship with the US."

Jacques said he has discerned a "grudging acceptance" among European leaders that the old days are largely over, which may lead to a more united EU.

"When you think all this has happened in a matter of days and weeks, people move at different speeds in the face of new realities. Some people do that very quickly, some people don't want to believe it, but I think that we are now in a situation where (we can see where) things are going to go.

"Europe's reactions to the shifts (will) probably have the effect of bringing Europe more together."