European defence officials call for earlier interoperability testing and open architectures

A Canadian drone pilot launches an FPV UAV during a in exercise by NATO's Multinational Brigade in Latvia in August 2026. (NATO)

Open architectures and early testing of prototypes were among the priorities raised by European defence officials at Apex Europe 2026 in London on 7–8 October. The officials identified interoperability and integration of crewed and uncrewed systems, cross-domain command and control (C2), and resilience to cyber and electronic-warfare threats as key mission areas.

Brigadier General Ilmars Lejins, deputy commander of NATO's Multinational Division North (MND-N), said about 4,000 allied troops in Latvia use “vehicles and equipment and systems that do not always work together”. He said MND-N had established a divisional experimental cell to test already-fielded equipment and provide faster feedback on what works. He urged countries with forces deployed abroad to work with host nations on interoperability trials, within their laws and regulations. He also said Latvia had established a legal framework for working with industry while complying with contracting and competition rules.

MND-N has forward elements in Ādaži, Latvia, while the rest of its headquarters is in Karup, Denmark.

Colonel Thomas Erlenbruch of the Bundeswehr's Cyber and Information Domain Service said his organisation verifies, validates and accredits C2 systems before they can be fielded. Testing should begin during development, he said, so that interoperability problems are identified before final accreditation. “We cannot allow industry just to give us black boxes; I have to be able to look under the hood,” he said.