Gen. Jay Raymond of the US Space Command recently stated that, as space becomes a full-fledged war domain, allies may offer us a much needed advantage. Though there are security risks involved, the US has already been working closely to train with partners in France, Germany, and Japan. The UK was the first to sign up for Operation Olympic Defender which prevents hostile action from space. Australia, Canada, and New Zealand are on board as well, but the Space Command is open to expanding even beyond that.
