ighter jets are among the most expensive weapons a nation can build, with costs running into tens of billions. Each new model costs more than the last.

No wonder, then, that Europe’s superpowers are squabbling over money when it comes to the latest jet project.

Development of the Système de Combat Aérien du Futur (SCAF) – or the Future Combat Air System in England – is increasingly opening up a rift between Paris and Berlin.

Germany and France, who together with Spain are developing the SCAF, are increasingly at odds over how to fund the project, where it should be built and who the jets should be sold to.

“One or two of these issues on their own is fine,” says Rym Momtaz, a fellow of European Foreign Policy and Security at the IISS think tank. “But all of these combined are just making for a difficult moment and the Franco German relationship.”

The SCAF project has its roots in a 2001 effort to find a successor to todays’ fighter technology but it began in earnest in 2017. SCAF aims to have a working warplane by 2040.

The forthcoming jets will be more like a flying supercomputer than the flying gunners of the past. As well as carrying munitions, they will capture pictures, radar data and radio traffic, interpreting it at a thousand miles per hour. As a result, development costs are high.