Anduril has a novel pitch for Britain’s military: If it wins a £100 million ($133.5 million) contract for a new uncrewed combat aircraft, the company will foot half the bill for development.The California defense startup made the same proposal in Australia, and in September landed a A$1.7 billion ($1.1 billion) contract there to build an autonomous submarine. In Europe, which is embarking on a historic rearming effort, even more money is at stake....