When Monocle interviewed Kaja Kallas in Tallinn in 2021, she had just become Estonia’s first female prime minister and was contending with the coronavirus pandemic. Four years later, when we meet again in Brussels, she is the EU’s de facto foreign minister and is preparing for a week of summits focused on ratcheting up the bloc’s defence capabilities.

A lot has happened since Tallinn: back then, the 44-year-old Kallas seemed to typify a new generation of leaders including Sanna Marin and Jacinda Ardern – female liberal internationalists, often better liked outside their home countries than within them. It was assumed that all three were destined for a big multilateral institution but Kallas is the only one who has made it. The reason for this might be summed up in one word: Ukraine.

In 2021, as Russian troops began massing on Ukraine’s borders, she was among the few European leaders who called out Moscow’s intentions. During the first two years of Russia’s assault, Kallas was vocal about the need to provide as much assistance as possible to Kyiv. When Jens Stoltenberg was approaching the end of his tenure as Nato’s secretary-general, she was seen as a leading candidate to replace him. That position went to former Dutch prime minister Mark Rutte. But a few months later, in July 2024, Kallas resigned as Estonia’s leader to become the EU’s chief diplomat. When she assumed that role in December, the work of sustaining wavering EU support for Ukraine had been made more difficult by the Middle Eastern conflagration unleashed by the 7 October attacks. Donald Trump’s re-election as US president a few weeks earlier made this already tricky job even thornier. While other European leaders have sought to placate the White House, Kallas has been forthright in her new role. On her first day, during a visit to Kyiv, she tweeted, “The European Union wants Ukraine to win this war” – a declaration that received immediate censure from other EU leaders for its bluntness.

In many respects Kallas represents much that the Trump administration professes to despise – inextricably linked to Brussels (before becoming Estonian PM she was a member of the EU Parliament for four years) and bellicose in her anti-Putin rhetoric. There have been reports of US officials criticising the “Estonianisation” of EU foreign policy – an overtly hostile anti-Moscow line. After travelling across the Atlantic in February to meet her newly installed US counterpart, Marco Rubio, Kallas had her appointment unceremoniously cancelled. Since then, she has declared, “The free world needs a new leader,” while pushing for the confiscation of Russian assets frozen at the start of the war. Still, when we meet at the EU Commission’s HQ, Kallas seems unruffled. She has just returned from a stormy UN General Assembly in New York and is about to attend meetings focused on, among other things, responding to recent Russian violations of EU airspace, which included the incursion of three MIG fighter jets into Estonian skies.

You’ve just been at the UN General Assembly [UNGA], where Donald Trump made a speech attacking the EU, the UK and other US allies. After such a speech, is it still appropriate to describe the US as an ally?
Yes, the US is an ally. We don’t always see eye to eye and, of course, President Trump has his own style. But when it comes to actual issues, we still work with America, which remains our biggest ally.

Were Trump’s attacks on the UN as an institution proof that multilateralism is dead?
Multilateralism is under heavy fire. But around the world, many people are wishing for it because of the global challenges that we face. We can only address them together. At the UNGA, I took part in a lot of multilateral forums. We had a meeting with the African Union; I follow former Belgian prime minister Paul-Henri Spaak’s maxim. He said that there are only two types of countries: small countries and those that haven’t yet realised that they are small countries. For these countries, international law and the multilateral system are of utmost importance but what they require is reform. Look at the UN. On some levels, it doesn’t really reflect the world today. Take the Security Council. Who has veto rights? Considering that Russia, a Security Council member, has attacked another country and gone against all of the rules of the UN Charter, it’s clear that we need to look into this and develop those rules further so that they can actually address accountability.

Is the US president a force for good or ill?
The president is elected by the country’s citizens and we have to work with all the presidents that our counterparts’ electorates elect. It’s not up to me to comment.

What are your thoughts on the suggestion that the EU acceded to an unfair trade deal with the US in August due to European countries being reliant on Washington for their security, as well as support for Ukraine – and because Brussels feared that these would be under threat if the trade deal was rejected?
It’s clear that we have been quite reliant on the US. European countries have woken up and now invest more in our defence. We will bring a lot of funding to be more autonomous in that sense, because every dependence you have makes you vulnerable.

How damaging is the dispute between France and Germany over which company should lead a project to develop a next-generation EU fighter jet? Is this proof that the bloc’s members will always think first about what is best for themselves?
We have long considered defence to be a national issue but the Ukraine war has shown us that it’s regional, which means that we need to work together. It’s clear from reading the latest EU defence-readiness road map that we have to work out how we can encourage member states to co-operate and come up with more joint projects. When it comes to big problems that require us to co-operate and support each other, things have to be interoperable. If systems have been designed for one country, they’re not interoperable with, say, the ammunition coming from another. And that’s detrimental to our security.

What is the most important thing to get right for European defence?
We have nine critical capability areas that we have to develop. To mention just a few: air defence, artillery systems and missile and ammunition production. Then drones and anti-drone technology. We just had a good meeting regarding the drone wall; we’re learning from Ukraine how they have done it and how it should work.

British journalist Gideon Rachman claims to have heard members of the US government decry the “Estonianisation” of EU foreign policy. What do you take this to mean?
Well, I guess it means that the Estonian foreign ministry has done a good job. Jokes aside, it is clear that every leader of European foreign policy has brought his or her ideas to the table. So, if we look at foreign policy now, we’ll see that it’s being driven by what’s happening, what Russia is doing. Clearly, that is our biggest threat, agreed by everybody in the European Union, which is why we have to act accordingly. So if “Estonianisation” means being more agile and reacting faster, I think that it’s a positive thing.

What should be done if Russian jets violate Estonia’s airspace again?
Estonia is a Nato country and, like President Trump and different EU leaders have said, there are clear protocols for how we should act in Nato if such things happen.

So you agree with Trump’s remarks that they should be shot down next time?
It is up to those who make those decisions. Russia wants to do two things. One is to stress to us how far it can go in terms of pushing the boundaries – today I saw on the news that drone attacks are happening in other countries in Europe too. The other is that it wants to sow fear in our societies. So we have to be prepared. The more prepared we are, the more ready we are to act. And if we are ready to act, that reduces the fear in our societies.

What would demonstrate Europe’s and Nato’s ability to react?
Russia only understands strength, so the response has to be very strong.

You have said that European and Nato countries must ensure that Russia doesn’t attack another sovereign nation again. How can they do this?
We have two lines of working. One is to put pressure on Russia so that it comes to the table and stops the killing and doesn’t do this again. And that’s why we’re imposing sanctions, so that they run out of funding to finance wars. The second is to help Ukraine, because it is defending itself. If you think about European countries, they had to lose their last colonial war [in order to change course]. Russia hasn’t lost its last colonial war.

Do you agree with Trump that Ukraine can win back all of its territory lost to Russia?
Yes, if we provide it with the necessary means and support. Ukrainians have the resolve and they are not surrendering. When I speak to them, they say, “Yes, we can do it, if you and the Americans help us.”

What do you think is the likely end game for this war?
It depends on us. And by “us”, I don’t mean the European Union – I mean all of the countries in the world who support the multilateral system and international law. If the aggressor walks away with more than it had before, then aggression has paid off – and that is dangerous for every country.

What has the Israel-Gaza crisis taught you about European influence in the Middle East?
It’s very close to our neighbourhood. So whatever happens in the Middle East has a direct impact on our countries as well. We need to work together with all of our partners in that region to have stability there. We have leverage if we are united and, of course, on many points in the Israel-Gaza conflict, we don’t have that unity. But at the same time, I would stress that there are a lot of areas where we have unity. All member states support the immediate release of the hostages, a ceasefire and the ending of hostilities. All member states support delivering humanitarian aid at scale to Gaza and that it shouldn’t be hindered in any way. And all member states agree on the two-state solution and believe that Hamas should have no role in the future governing of Gaza. So there is a lot that we agree on and we are trying to build on those things.

The aid deal that you helped to negotiate in July was lauded at the time. What do you think about its impact today? And did the Israelis keep up their side of the deal?
Before July, there were zero trucks getting in. After the deal, about 2,000 trucks were able to enter Gaza. Of course, that’s not enough but it’s better than zero. Israel agreed and also opened the Egyptian and Jordan routes, the border crossings. It also started to repair the critical infrastructure as it had promised, such as water desalination and water provision. So a lot of that was implemented. It’s an issue that we don’t really have our own monitors, so we are reliant on the numbers that come from the UN, which the Israelis are questioning. The numbers that we get from the Israelis – such as how many trucks are coming in – are concretely very different from the ones that we get from the UN. Because we don’t have our own eyes on the ground, we rely on these international actors that are on the ground, which puts us in a bit more of a difficult position.

Do you think that recent moves by European countries to recognise the state of Palestine were a good idea?
It’s up to member states to decide which countries they recognise and which they don’t. But it derives from this support for a two-state solution. That’s why the EU is also supporting the Palestinian Authority more than anybody else. We will give it €1.6bn from 2025 to 2027. Will [recognition] have an immediate effect on stopping the killing in Gaza? I don’t think they’re so much interrelated. It’s more about sending a signal that we want to keep the two-state solution alive.

Do moves by EU states such as the recognition of Palestinian statehood or bilateral security deals with non-EU countries suggest a weakening of centralised decision-making?
On Ukraine, we have been very united. Israel is the toughest issue because member states have very different historical backgrounds. But again, I would stress all of the points where we agree and where we have a common foreign policy, rather than those where we don’t. We are made up of 27 democracies, which means there are 27 different public opinions.

Historian Timothy Garton Ash described you as a “child of ’89”. What is the biggest lesson that we can learn from the collapse of the Soviet Union?
We should not be afraid of democracy expanding because the leaders of democratic countries are held accountable every four or five years by their voters. If they do something irrational, such as attacking another country, they are voted out of office.

What is the role of the EU Commission in a more geopolitically fractious world?
These challenging times have given us the opportunity to play a geopolitical role. And what I want to stress here is that when I go around the world, meeting the leaders of other regions and countries, Europe is perceived as a credible and reliable partner, and considering the ongoing trade wars, we are still believers in free trade. A lot of countries are also looking towards Europe to diversify their trade portfolios, for example, or their relationships in general when it comes to critical raw materials. What we should do is act as a geopolitical power. It means that if the world has become more transactional than it has ever been, we should take that into account. If a geopolitical actor has a problem – as we have, for example, with Russia and its war in Ukraine – then you should make very clear what the objective is or what you need from them to respect your interests and your concerns. We haven’t always done that, because we have been the good guys, always coming with the development aid and not asking any questions.

Geopolitical power can be based on two things. One is your military power – and we are not there yet. We are building our militaries and defence. But the other is economic power and we still have a lot of that.