TOWARDS THE end of last year a pair of military satellites, one American and the other French, prepared for a delicate orbital minuet. They were about to conduct a so-called rendezvous and proximity operation (RPO)—in which one or more satellites approach another to inspect or manipulate it—near an enemy satellite. They have not said which, but it is not hard to guess. “The French have talked about Russian manoeuvres [near French satellites] over the years,” says General Stephen Whiting, speaking at the headquarters of US Space Command in Colorado Springs. “And so…we demonstrated that we could both manoeuvre satellites near each other and near other countries’ satellites in a way that signalled our ability to operate well together.”