'Proponents of SSP's argue that with a price as little as US 250 million, compared with US 2 billion for the new Virginia-class SSN the US Navy could get eight AIPs for the price of one SSN. The Maths may be undeniable and the advantages in some circumstances debatable, but for the US Navy and its unique operating requirements, the case for a US-flagged advanced SS or AIP submarine is thin indeed.'