She’s been called the “Goblin under Google’s bed”, and her actions could force big U.S. companies to pay billions of dollars in fines.

She’s Margrethe Vestager, the EU’s new competition commissioner, who is living up to her nickname “The Iron Lady of Denmark” by taking on industry giants such as Google GOOG, -1.97% , MasterCard MA, -2.21% , Starbucks SBUX, -1.24% and Amazon AMZN, +0.18% .

Vestager arrived in Brussels in November and promptly kick-started moribund competition investigations back to life. After five years of inquiries, the competition commission in April finally slapped Google with formal antitrust charges that could cost the tech company $6.6 billion in fines, if its online search is found to be unfair to rivals. Also on the docket: Probes into Apple’s tax arrangements, General Electrics’s bid for Alstom and Gazprom’s pricing, among others.

And the new antitrust chief has added to that list since taking up her role. She‘s opened a sweeping inquiry into e-commerce companies’ cross-border trade, which could involve questions for eBay EBAY, +3.14% and Netflix NFLX, +3.70% . In July, she took aim at MasterCard, accusing the credit-card company of artificially bumping up costs of card payments for retailers. In her latest set of charges, she’s targeting six major U.S. film studios, including Disney DIS, -2.50% , and Warner Bros. US:TWX, alleging they in collaboration with Sky UK UK:SKY restrict EU consumers’ access to pay-TV services.

Her team is also looking into whether Google, using its Android clout, has illegally blocked the development of rival operating systems, apps and services.

That enthusiasm for the fight has made the Danish politician-turned-bureaucrat unpopular with some companies, which perhaps remember the hefty antitrust fines levied by the EU on Microsoft (2.2 billion euros, or $2.45 billion) and Intel (€1.06 billion). In the U.S., they call her protectionist and anti-American, while in Russia, there are claims she’s plotting — with the U.S. — to bring the country to its knees by targeting its important gas sector.

But Vestager has a reputation for toughness, stemming from her time as economics minister and deputy prime minister in Denmark. She managed to push through the Radikale Venstre party’s centrist agenda in the face of strong opposition, earning her another nickname: “Margrethe III” — implying she was almost as powerful as Danish Queen Margrethe II and had more political influence than the then-prime minister.

Over her career, the 47-year-old has racked up a laundry list of accomplishments, from becoming Denmark’s youngest-ever female minister to being its first politician to give birth while serving in cabinet.

So it’s all the more impressive she comes across as sweet, polite, open and thoughtful — the kind of politician you could share a sandwich with. And she’s smart. In fact, she’s the inspiration for the lead character in Danish series “Borgen”, Hillary Clinton’s favorite TV show.

MarketWatch met Vestager in her home town of Copenhagen in late May to find out why she’s putting U.S. majors in the antitrust hot seat, how she deals with criticism and how she means to make the EU marketplace more fair.

MarketWatch: What’s the motivation for laying antitrust charges against Google?

Vestager: It was obvious that Google has had enormous success in the European market with its general search result pages. That’s great, and in itself, not a problem.

But if we believe we have data that support our suspicion that a company is abusing its dominant position, then we have to lay it all out, so the company knows — in writing — what we think and can respond to it. Because, of course, they have the right to defend themselves and say, “You are absolutely wrong”.

“ We’ve worked really hard on the case, but now the ball is in Google’s court. ”

MarketWatch: Google is also dominant in the U.S. market, though to a smaller degree than in Europe. Why aren’t American authorities investigating these issues?

Vestager: It depends precisely how big their market share is at home. That’s crucial, when it comes to legal questions and how things are investigated. Google’s market share is smaller in the U.S. (about two-thirds), where it’s around 90%-95% in some European markets.

Here in Denmark, its market share is also extremely high, and it’s become a part of the Danish language: “at google” (to google), meaning to find something on the internet. That tells you something about Google’s success in the European market.

MarketWatch: What has Google said about the charges so far?

Vestager: The communication from Google has been very low. […] We’ve worked really hard on the case, but now the ball is in Google’s court. Read: Google rebuffs EU on antitrust charges

(UPDATE: Since the interview with Vestager, Google has rebuffed the European Union’s demand that it change the way it ranks online comparison-shopping services in its search results, setting up a potentially drawn-out legal battle.)

MarketWatch: You’ve been called anti-American and protectionist. Is that something you and the commission are concerned about?

Vestager: Yes, very much. First, I think that’s a serious accusation; and second, that’s not the impression we’re hoping to give.

The tools we use when we look at mergers, investigate cartels — when we investigate abuse of a dominant position — they are meant to keep the single market open, competitive and fair. If we use those tools for political purposes, then we’d compromise them completely. The next people or company that came under the commission’s spotlight would then ask: “Why? Is there something wrong with my flag or my ownership?”

That’s why I take this very seriously, and when I dive into the numbers — and I’ve also asked coworkers to check out how it looks under previous commissions — then you can’t find any bias.

I think it more has to do with what countries are successful at. For example, historically, there have been many probes into financial markets in the U.K., because it’s a financial center. There have also been lots of investigations into the chemicals industry in Germany, which is a big player in the chemicals industry. And maybe it’s a bit of the same with the U.S. — that they are really big on technology and IT.

MarketWatch: But do you understand why this list of U.S. companies has made some people perceive you as anti-American?

Vestager: I actually don’t. And the reason I react so strongly to this is because I’m from Denmark, and in Denmark we love the U.S. I don’t have anything personally against the U.S. — on the contrary.

We think it’s crucial that the EU and the U.S. together set the standards going forward in a whole range of areas. So no, I don’t think we’re anti-American.

There are thousands and thousands of American companies that do business really well in the EU without ever getting in the spotlight of any kind. Because they operate by the book, and that’s it.

“ In Denmark we love the U.S. I don’t have anything personally against the U.S. — on the contrary. ”

MarketWatch: Do some U.S. companies need to get a better understanding of European culture and law, so they don’t end up in these cases?

Vestager: I don’t think it makes a difference that they are American. If Google had been European, I think it would have been the same. When I ask at home — I have three daughters at the age of 12, 16 and 19 — why they use Google so often, they never say it’s because it’s a fantastic American company. They say, “Mom, it’s because it works”.

MarketWatch: What kind of complaints have you received about Google, and from whom?

Vestager: They’ve come both from competing companies and consumer-protection groups — from companies large and small, from companies close by and others far away.

Plus, we still have other ongoing investigations into Google, as the statement of objection we’ve issued only covers the way it handles its shopping-comparison services.

[We’re also] investigating neighboring services that are very similar — travel, maps, etc. Another category where we started to get complaints a few years ago is about how Google handles its advertising businesses. […] Another inquiry centers on copying third-party data and using it as your own — so-called scraping.

MarketWatch: Why is this an issue for the consumer or other companies?

Vestager: There’s a risk that if you can’t be found on Google, then you have no incentive to invent something new, and that can stifle the innovative part of our business community. That’s a shame for the consumer. If innovation comes to a halt, we have to settle for “state of the art 2014”, and I’m not sure that’s for the best. It probably isn’t.

MarketWatch: But why are you filing these charges now? The investigation against Google has been going on for five years.

Vestager: There was a process, where my predecessor chose the path of negotiations and said to Google: There are some things we disagree on, but you don’t have to respond to that or say, “We did it”. The commission spent a lot of energy on that.

There was one round of negotiations, there was one more and then a third round, but we didn’t really get anywhere. And if a strategy that you put so many resources into looks like it’s failing, then I don’t think you should waste any more resources on that. Instead, you have to say, “Okay, we tried that — we really tried that — but it didn’t work, so we need to find another way”.

MarketWatch: So is this happening now just because you’ve been tough enough to take them on?

Vestager: I don’t see it at all like that, because I don’t have any issues at all with Google or Gazprom or whoever we’re investigating. […] I think Google is a fantastic company, and it’s fascinating, everything they’ve accomplished. But their behavior, when it comes to what we think of as abuse of a very strong and successful position — that’s where we have an issue. So I’m not at war with the company, but with the specific behavior.

MarketWatch: As for Gazprom, those charges come a year after the EU and the U.S sanctions against Russia. Have you thought about the timing and how it could be interpreted as adding more pressure?

Vestager: It’s the same as with the anti-American bias. I can’t compromise the enforcement of our competition legislation by using it politically. That’s why the timing of when we sent the statement of objection to Gazprom was just a matter of that’s how far we’d gotten in the process.

MarketWatch: But do you understand why Putin would say you’re trying to make Russia economically and politically impotent by targeting the gas market?

Vestager: No, I don’t understand that. Because this isn’t about Gazprom in Europe, it’s about Gazprom in five countries where we believe we have evidence they charged unreasonably high prices. It’s not an opinion or an attitude, but about a behavior that we believe is wrong. It needs to stand up in court and be based on facts.

MarketWatch: Overall, what do you hope to accomplish during your five years as competition commissioner?

Vestager: It may sound ambitious, but I really want to play in part in making Europeans feel they live in a fairer Europe. A more equal Europe. Where you can be sure, even if you’re just a small company or an ordinary citizen, that you have a fair chance.

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