Britain and Germany are entering a "golden age" of defence co-operation as they build a long-range missile designed to defend Europe against Russia. They have also largely turned the page on the tumultuous Brexit years, with old arguments over EU regulations giving way to joint defence projects to counter Moscow, including a closely guarded long-range missile programme. Two versions of the DPS missile are under consideration: a low-flying cruise missile which flies under Russian air defences, and a hypersonic missile which travels at five times the speed of sound. Advertisement AdvertisementAdvertisement AdvertisementOn the German side, officials are optimistic about the DPS programme but do not see it as the "centre of gravity" on long-range missile projects. Helsing, a German defence firm which specialises in AI, recently opened a hi-tech underwater drone factory in Plymouth to produce surveillance drones.