LONDON, July 4 -- Europe has been talking about building its own next-generation fighter for a decade. On Thursday, three of the governments that have actually been paying for one put £4.6 billion behind the conversation.

The United Kingdom, Italy and Japan formally awarded the contract to Edgewing, the joint venture of BAE Systems, Leonardo and Japan Aircraft Industrial Enhancement Co., that takes the Global Combat Air Programme from an engineering concept into full design and development. The contract, signed through the GCAP Agency, provides Edgewing with the funding to design the aircraft, conduct structural and systems testing, and produce a prototype expected to fly before the end of 2027. If that timeline holds, the three gov...