HMS Queen Elizabeth: Why is a UK aircraft carrier going on a world tour?

Dr Peter Roberts, director of military sciences at RUSI, a defence and security think tank, says that instead of what he calls "a predictable, long and slow deployment", the Royal Navy could have dispatched two of its hunter-killer submarines. If they set off north, under the Arctic ice, and then popped up in the Pacific, he suggests, that would have had a greater impact on challenging both Russian and Chinese behaviour.