Rym Momtaz, Hans-Dieter Lucas, and Pierre Vimont discuss how Europe can build credible defense capabilities within the NATO framework.
With Washington insisting that Europe take primary responsibility for its defense, European leaders need to develop a roadmap and command structure of their own.
Rym Momtaz, Hans-Dieter Lucas, and Pierre Vimont unpack why European capabilities must become separable, though not separate, from NATO, and how to get there fast.
This discussion draws on the article:
Hans-Dieter Lucas, Adam Thomson, and Pierre Vimont, “Separable, not Separate: Governing Europe’s Collective Defense,” September 30, 2026, Carnegie Europe.
Rym Momtaz
Hello and welcome to this episode of Europe Inside Out. I'm your host, Rym Momtaz, the editor in chief of Carnegie Europe’s Strategic Europe, where twice a week we publish punchy, short analysis on all things strategic in Europe. And today well, we're in the heart of all things strategic in Europe. We're going to talk about that hot potato that is the concept of NATO 3.0, the future of European security with less, and perhaps in some ways and in some instances, no United States. And to take apart that very fundamental issue and question, I'm very happy to be joined by Carnegie Europe's Pierre Vimont, a former French and European diplomat, of course. And Hans Dieter Lucas, a senior fellow at the Center for Strategic Security and Integration Studies at Bonn University, and of course a former German Ambassador to NATO.
Rym Momtaz: So you both just wrote a very thought provoking, interesting article for Carnegie Europe, along with Adam Thompson. And your article is titled “Separable, Not Separate, Governing Europe's Collective Defense.” So you start your piece with a sentence that I found very striking. You say, and I quote “European governments can no longer confidently explain how Europe's collective defense will be insured.” And then you add, and I quote, “modern America might be increasingly unlikely to come to Europe's defense in a major hybrid or high intensity conflict with Russia.” And finally, you conclude that the way forward is for “European capabilities to gradually become separable, though not separate, within the NATO framework, in case the United States is not willing in one instance or many, or able to engage in a European conflict.” Maybe Hans Dieter, you can start. Why do you think that European governments can't explain how collective defense is going to be ensured?
Hans Dieter Lucas
Well, for many decades NATO was based on the assumption that the U.S. would be fully engaged in a military conflict in Europe, based on an ironclad commitment with regard to Article 5. But, I mean, the last years have shown us that, this commitment has become rather doubtful. I mean, we've seen that President Trump has called NATO a paper tiger, that he's threatened close military allies with the use of military force in Greenland and Denmark. He has also made some, I mean rather unclear statements with regards, I mean to nuclear deterrence, et cetera, et cetera. And there's of course a general tendency in the U.S. to get rid of foreign entanglements, alliances, et cetera, et cetera, the pivot towards Asia. There is also more focus on Western hemisphere. So that clearly goes beyond President Trump, goes beyond the MAGA movement. So in that respect, I mean the critical conclusion for all that is Europe must be more able to defend itself than in the past. And that will require at the end of the day, not the end of NATO, but certainly a transformation of NATO.
Rym Momtaz
But Pierre, I mean I think it's very interesting coming from a former German diplomat that you are I think so blunt and clear eyed on the general direction of travel in the U.S. As an American citizen, I think you're right. I think it's a bipartisan change in, in the perception of the American population and, and certainly American politicians. Pierre, when you say why can't the Europeans explain how Europe's defense is going to be insured? What is so difficult for European countries that are by all means some of the wealthiest, most industrialized, most developed in the world, why aren't they able to articulate that?
Pierre Vimont
Rym, I think it is because Europeans have been for a very long time in denial of the new reality. For many years, in fact, Europeans have relied on American military support. Their military expenditure were going down endlessly and it's only in the last few years that they have decided that they should do something about that. But with still the assumption that America would still be there on their side. And as Hans Dieter has just said, something has changed there. And they have gone from some sort of denial that the Trump administration was bringing something new political security landscape and that they had better take this into account and accept new responsibilities. I think they have reached that point now. But what our paper is saying is that they have to go to the next stage, which is to start planning, where do they go from here? It's all very well to talk about NATO 3.0, to talk about the need for a 5 percent of their GDP dedicated to military expenditure and building up their capabilities. But there's much more to do than that, starting with a European collective defense. And this is where I think Europeans are still dragging their feet, to some extent. And waiting for something that will not appear unless they take their responsibility and decided to do something about it. You remember the first Trump mandate, at the beginning of 2017, when the then German Chancellor Angela Merkel said that something had changed and Europe had to take its destiny into its own hands. I'm not sure they have done it yet. And I think this is what our paper is all about. How maybe to move in that direction now, quickly, swiftly, because we need to move fast.
Rym Momtaz
Can we maybe talk about something that is perhaps uncomfortable? I have a former German diplomat, a former French diplomat. I feel like I need to perhaps very early on talk about maybe the elephant in the room, which is the difficult current situation between France and Germany when it comes to big defense industrial projects. Let's talk about that to start with. But also, beyond that, it seems that France and Germany are butting heads on the general sort of strategic direction, how the relationship with the United States needs to be transformed, what it should look like moving forward. So maybe let's go into that because I feel like if we, if this continues, how can the Europeans then go through the transformations that you are discussing that are very profound and will need leadership, at least co-leadership between France and Germany, and then maybe we can talk about the problem of leadership in general. So, maybe Hans Dieter, do you see a moment in the next few months where France and Germany are going to be able to find a modus operandi on these issues?
Hans Dieter Lucas
Well, I think we need to differentiate, as far as the political aspect is concerned. I've seen sort of more convergence over the last years. I think one of the results of the Zeitenwende is that Germany in some respect has become much more French, when it comes to understanding the importance of military power. I mean, at that level, I think there is no real difference between Berlin and Paris. We have also contributed to all these European defense initiatives, namely SAFE, the European defense investment plan, etc.
Rym Momtaz
But isn't there a real divergence between the French who don't want to buy off the shelf outside of the EU anymore because they feel like every cent, every euro, needs to be invested in European defense and Germany that feels obviously the need to do things faster and sometimes need to buy off the shelf because, well, the production in Europe isn't there.
Hans Dieter Lucas
Yeah, that is exactly the case. So in that respect, I mean, there is a considerable time pressure, so many people say, also our intelligence services, that we have to prepare, maybe for a major contract with Russia by the end of this decade. I mean we have a huge capability problem and that needs to be fixed. And in that respect, I mean there's no other option than to buy capabilities which are available, means available also in the U.S. At the same time this does not exclude investing in a European defense industry. I strongly believe that Germany, with this huge defense budget has a particular responsibility, you know, when it comes to building a strong European defense industry. But we have also seen recently, I mean, I think of EFCAs and of MGCs, that at the industrial level, the national interest was very, very strong. And unfortunately, the political leaders have not really managed, I mean, to fix these strong sort of, divergencies at the level of the companies.
Rym Momtaz
So, do you foresee, on the practical side, the French and Germans figuring out at least a way forward in the next few months?
Hans Dieter Lucas
I think that would be desirable, I mean to pave the way, I mean for long term orientation and particularly with regards, I mean to the upcoming presidential elections in France. I mean that would be highly desirable. Whether this is possible, quite frankly, I don't know. At the end of the day also, I mean we need that. Even if, I mean we were able to make some important decisions right now, at the end of the day to make it sustainable, we need a sustained engagement, in Berlin and Paris for the coming years to make all this happen.
Rym Momtaz
Pierre, what's your assessment of a way forward? Is it as bleak as it seems from the perspective of someone like me?
Pierre Vimont
I mean, the German French relationship has always been a very difficult one. You know, contrary to what people tend to say because they look back at 40 or 50 years of a strong partnership, they always think that this partnership was a free flowing stream of joy and happiness. It was never the case. It has always been a struggle between Germany and France, for many reasons that date back to history because of our geopolitical positions in Europe, which are not exactly the same. But what has been important time and time again is that we always manage to overcome those difficulties. And even today, where it is true that with regard to the defense-industrial project this is today rather difficult. If you look at the aircraft and the tank project, which seem to be, now today, in a difficult situation.
Rym Momtaz
The FCAS and MGCs, which seem to be dead in many ways.
Pierre Vimont
Yeah, to some extent. But there will be a new revival and other ways of doing it, with other partners. And I'll come back to that in a second. But at the same time, look on the strategic element, the way now Germany and France are talking about the French nuclear deterrence, which was unbelievable a few years ago. And when Macron proposed to start discussing this with Berlin it was immediately accepted. And it's a major change in Germany that needs to be taken into account.
Rym Momtaz
France and Germany set up a nuclear steering group, around the idea of France's, proposal of forward deterrence.
Pierre Vimont
And could I add one additional point is that I think despite the fact that in our paper, the three of us, our British colleague, Hans Dieter, and myself are promoting the idea of a European three group as, the three leaders, we insist time and again on the fact that today you need more than only these three countries.
Rym Momtaz
And you mentioned explicitly Poland and Italy.
Pierre Vimont
Italy, Poland. But I'm thinking also about some of our Nordic partners, Sweden, Finland. And by the way, if you look, going back to what I was saying about the ongoing discussion around the French nuclear deterrence with Germany, it's not Germany that is being brought into this discussion. Many other European Union countries have decided to come along and to discuss about this.
Rym Momtaz
Yeah, there are 10.
Pierre Vimont
So I think there is a big change there, that our two countries, Germany and France, have to take into account where they can play a leading role, I think, but where they will not be the only one in the future.
Rym Momtaz
And so let's go into maybe the heart of your proposal, which is this idea of separable but not separate European capabilities within NATO. Can you explain that? Maybe, Pierre, you go first. What does that mean, separable but not separate? And second, what kind of specific capabilities do you have in mind?
Pierre Vimont
It's a rather simple idea, which, by the way, is not new. I think the first time this whole thing came out, even before it was being discussed in NATO, was when they had this meeting in St. Malo between, Britain, Tony Blair and France, Jacques Chirac about how to enhance European collective defense. And that slowly brought the idea of how inside NATO, European allies could find a way of using NATO capacities. Even if, in a conflict or a crisis, the United States decides not to join, how can we prepare ourselves for that kind of option? Which means we're still altogether part of NATO, so we're not separate. But if need be, having prepared for such option, European allies and non-European allies, I must add, allies who are in NATO but are not European, like Canada for instance, could start some operation and go ahead on their own with the consent of the United States, a green light from the United States, or at least if need be, no veto from the United States. So that was what we decided by the time of what we called the Berlin Plus. In fact it was put into action, as you know, in Bosnia Herzegovina, where it is in the name, on behalf of NATO, a European force alone, without the U.S. being involved there. And what we were thinking with Hans Dieter and Adam was that maybe this was the right template, the right place, the right frame where we could try again to build some kind of separable European capacities in order precisely to secure that European collective defense we need. And how to prepare for that and how to work inside the structures of NATO in order to have this capacity, if need be, even against an adversary as powerful as Russia in the future.
Rym Momtaz
Okay, what Pierre just said is very interesting because if you take the example of the Bosnian war, the American intervention was key in stopping the war and opening the way for an EU or rather a European force. But the specific scenario you guys talk about in your article is very specific about an attack by Russia. And so Russia is a much bigger problem, security wise than the Bosnian war was in terms of just the core of the national security of European countries. So on this, Hans Dieter, like, what are we talking about specifically in terms of capabilities? Because what we know is that today the NATO connective tissue, the way the whole thing works is very much based on American command and control, American strategic enablers, all of which the Europeans still have a long way to go in order to be able to replicate, even in terms of their ability to coordinate a high intensity war with multiple, armies, and brigades without the United States. So what are you talking about specifically?
Hans Dieter Lucas
Exactly that, I mean that is the directions which we should be taking. That's not the case today. But I mean, I mean we have to go for it and also the recent U.S. national security defense strategy clearly speaks about Europeans having to take over the primary responsibility for their conventional defense. So that is what exactly the Americans are expecting from us. And that means if, I mean if we take this seriously, primary responsibility, that means to be able to defend ourselves in all domains, in all five domains. Land, sea, air, cyber, and space. So I mean this is really a huge talk ahead of us. There is no other way. A very sensitive question is of course, what does that mean for the nuclear question? And in that respect the U.S. Security strategy still speaks about the U.S. providing the critical nuclear umbrella for Europe. But also on that question, I think we need to have a discussion on the question which sort of increased role the French and also the British nuclear forces can play when it comes to NATO's nuclear deterrence. So there is a whole range of sort of very difficult questions which we have to tackle right now. But I think we have to do it and we have to do it with the U.S. in coordination. I think to do this alone, it would be a recipe for disaster. We need to discuss all these questions with the U.S. but we should not wait always for the U.S. to come up with proposals, but develop our own thoughts, our own initiatives. And that is what our sort of little piece is all about, that we say, well I mean it's high time that the Europeans do not only talk about capabilities, drones, space, tanks, etc. Etc. But also what it means sort of in terms of the political and military decisionmaking process. And you're absolutely right. You also need at the end of the day a European sort of see took on a control structure which would enable us at the end of the day to defend ourselves and to take action, if necessary, alone.
Rym Momtaz
What I like to call a nervous system, right, For a security and defense response. Hans-Dieter, I just want to follow up on one thing which you said, you know, in coordination with the United States, talking to the United States about building up these capabilities. But in your article you raise a very central question which is what if Washington won't cede a stronger role to non-U.S. allies while at the same time in the national security, in the national defense strategy, they say clearly that the Europeans need to take primary responsibility for conventional security and deterrence in Europe. Aren't we already in that situation? Isn't there already some tension behind the scenes where the U.S. wants the Europeans to take over the conventional side, but is having a hard time giving, or allowing, the Europeans to make decisions like grownups about certain things that may make them uncomfortable? Are you sensing that?
Hans Dieter Lucas
I think that's clearly there. I mean, this tendency, but at the end of the day, this transformation of NATO also requires a transformation of mindsets on both sides of the Atlantic. I mean, for us, I mean that we have to be more self-conscious, that we first of all need to develop the necessary capability which is the basis for everything else, but at the same time that the U.S. need to learn that, of course, when it comes to EU security, I mean, and if they think really that we should take over primary responsibility or defense, you must also have the possibility to take these important decisions which are crucial for our security.
Rym Momtaz
Pierre, doesn't this raise really profound questions about escalation management among the allies?
Pierre Vimont
Yes, it does, and we are witnessing that today with the hybrid war we're facing. But just going back to what you were saying earlier, what in fact this whole paper is pleading for is that as we see in the National Defense Review, as you rightly say, that the American side is pleading for the Europeans taking primary responsibility in their conventional collective defense. We're saying, let the Europeans take the Americans to the words, just do it and let's do it in an orderly way. In other words, have a plan, a sort of roadmap for the five years ahead where on all those different issues, the enablers, the different capacities where Europe at the moment is failing, to reach out and get up to that level. And from there on giving the Europeans the ability to master a conflict if it happens in the way they want to do it. Does it mean that, there is a risk of escalation? Yes, of course. But there is one time and again, since the start of the Ukrainian conflict four years ago we know that. And I'm not all that sure that we have been all that good at this escalation management. And I think we need to start looking on our own about how to handle this. But to do it inside NATO, as much as we can, because this is where the governance lie. This is where all the command-and-control system is, where the operational planning has been going on for many years. And we think that this is the right place where we could try to do that. That doesn't prevent Europeans to keep on doing their own homework inside the EU or in other places if they want to be. I want it to be the coalition of the willing, the Joint Expeditionary Force, with the eight EU nations working in the northern part of Europe. But there is a complementarity there that we think should be used as much as possible. But at the end of the day, it's all about the Europeans planning that future at last and acting in that direction. This is really what it's all about.
Hans Dieter Lucas
I mean, separable means not necessarily separate. We still think that. I mean, for the foreseeable future, the U.S. will be part of NATO. And of course the ideal solution will always be, you know, if it comes to a conflict with Russia, that the Americans would be on board, of course.
Rym Momtaz
So I think this is very interesting what you're saying, because, yes, maybe the U.S. is going to still be in NATO. What do you factor in a scenario that seems, could be in the very near future happening where the United States makes a deal with Russia that is at the expense of the Europeans. Where does that leave your recommended scenario for European security?
Hans Dieter Lucas
Our proposal goes absolutely in the right direction so that we have to take our destiny in our own hand. But so far we managed to prevent the Russian-American deal over our heads and also the heads of the Ukrainians. And that will be the case also in the future cannot be excluded, of course. But, as I said, I mean, the ideal solution would be to act together with the Americans. But we cannot be sure that this will be the case. So in that respect we need to go for this “separable but not separate.” That means the U.S. may stay in NATO. The U.S. will not sort of leave the Washington Treaty. I mean, that would require a sort of a decision by U.S. congress. I don't see that for the foreseeable future.
Rym Momtaz
Pierre. Maybe a difficult question to end, which we touched upon at the beginning. If this happens, who's the leader? Because America in a way has been the convenient outside arbiter between Europeans who couldn't agree on who should be in the lead. And when you're fighting a war, by necessity there has to be a leader at some point. So who among the Europeans could do it that would be accepted by everyone?
Pierre Vimont
It's a very good and a very difficult question. You're right, because as we see today, there is no strong leader, at the moment, on the European, screen, I would say. In most of the countries we have weak leaders facing strong opposition. And we sense that, as we're witnessing still today with this ongoing European Council, that the whole thing, the whole European workshop system is getting more and more difficult to bring forward. Yet, I think if we try to answer the question, as the collective defense of Europe becomes a priority, and that leaders, even weak leaders, cannot leave the question unanswered to their citizens, who time and again will ask the question, are we being defended in the proper way? I think this will bring about, as we are witnessing already in a very pragmatic way, some kind of collective leadership appearing time and again. We've seen it with the Coalition of the Willing. You remember when, there was this extraordinary meeting in Anchorage, Alaska between President Putin and Donald Trump, how the Europeans managed to find some seven of their leaders moving quickly to Washington to explain that this was not acceptable for Europe. And by the way, coming back to the question you were asking earlier, I'm not sure you could come out with an agreement between only the U.S. and Russia on Ukraine, because the Europeans have a foot in the door. They have assets there, they have leverage and you can't just dismiss them and leave them aside. So I think at the end of the day some kind of collective leadership will slowly emerge. And this is what is important because once you have that, then you can appoint the right person, you know, the right military people, who will do the homework and prepare. This is what we do in the European Union. You know, we have a single head of the military staff, we have one single head of the military missions in Brussels. So it's very possible at the end of the day to set up a whole military system from the European side. That makes sense. And it is ruled by a collective leadership among the leaders in the European Union who really want to move forward.
Rym Momtaz
Well, you've both certainly given us a lot of food for thought. And we've run out of time, but I'm sure we will have another opportunity to discuss all of this. Thank you both so much for making the time to join us.
And thank you to our listeners for joining this month's episode of Europe Inside Out. For those who are interested in learning more about Europe's security and EU-Russia relations, I encourage you to follow the work of Carnegie Europe on X and LinkedIn. Our producer is Matia Bagherini.