frank gardner reports. silent and stealthy. a nuclear—powered submarine on patrol. only six countries in the world have them — but now, under a new pact, britain and the us will help australia build its own fleet of them. they won't be carrying nuclear weapons. western nations have been stepping up their naval presence in the indo—pacific region — concerned about what they see as aggressive actions by china. the new pact, called aukus, is being called one of the most significant security partnerships in decades. one of the great prizes of this enterprise is that australia, the uk, and the us will become involved in a project that will last for decades. today, we're taking another historic step to deepen cooperation among all three of our nations. because we all recognise the imperative of ensuring peace and stability in the indo—pacific