There’s a tale of two fighters underway in Europe. And countries — and their companies — are choosing sides.

The latest news came during the DSEI expo in London. First, on Sept. 10, the Italian and U.K. governments signed a pledge to cooperate on the Tempest next-generation combat aircraft. A day later, BAE Systems and Leonardo formalized a partnership for development. With Leonardo comes Avio Aero and Elettronica, adding to the team of MBDA and Rolls Royce already on board. Likewise, Italy joins Sweden — the first country to sign onto the Tempest team with the U.K. back in July.

So these countries stand in one corner.

In the other corner is Germany, Spain and France — united in development of yet another next-generation fighter for Europe, the Future Combat Air System. (The program is known in France as SCAF, or Systeme de Combat Aérien Futur.) That trio (thus far) brings the industrial expertise of Airbus and Dassault.

Of course, nobody has said officially that this is an either-or scenario; maybe Europe, decades from now, will end up with two systems of systems as they’re each being presented. But when you consider the expense, as well as the messaging coming out of NATO and the European Union about regional security, it would seem unlikely and counterproductive. While dancing around the topic somewhat, chief executive of the European Defence Agency, Jorge Domecq, did predict some level of convergence: “As always, thinking of the competitiveness of the European defense industry, we have to think of program sustainability.”

So then who might win? As one would figure, that depends on whom you ask. A lot of the conversation at DSEI — building upon the enthusiasm at the Farnborough Airshow in 2018 when the new fighter was first unveiled — seemed to favor team Tempest. Some pointed to the fundamental disagreement between Germany and France about the exportability of its envisioned components. (Berlin takes a more restrictive stance than Paris when it comes to potential buyers in the Middle East.) Others claimed that France would be less likely to share control, which in turn might make additional partners reluctant to sign on.

But consider arguments from the other side, many of which emerged at the Paris Air Show in June, where a model of the Franco-German next-generation fighter was unveiled at Dassault’s chalet. The U.K. will soon not be a part of the EU, for one thing. That leaves some uncertainty on how regional cooperation might work, but also over whether the U.K. can pursue such an ambitious program amid political uncertainty. Some point to Italy, too, which has also struggled for political stability. And both countries face budget problems.

Then consider the industrial base for these teams. All countries involved in either program will expect a healthy portion of the work to land in their backyards. How might that work? Is it practical? Perhaps it would borrow from the model of the F-35, where the U.S. funded the bulk of development and partner nations contributed a portion in exchange for subcontracts to manufacture components in their own countries. But really, has that model proved so successful that it should be replicated? Perhaps it’s too soon to say, but it’s certainly brought with it a share of challenges (just consider the state of Turkey’s role, for example). On the other hand, regional cooperation is not new to Europe.

Or maybe this whole exercise — pursuing two systems, lining up manufacturers, recruiting partner nations — should be viewed as something of a downselect process to identify what practically makes the most sense as a region. Or perhaps even this will serve as a test case for how European allies will cooperate post Brexit. Regardless of which platform or platforms are ultimately developed, cooperation between the EU and the U.K. will need to be well-defined.

Or maybe we’re all just getting ahead of ourselves.