“Is Article 151(1)(c) of the Principal VAT Directive to be interpreted 5 as exempting a supply in the UK of services of dismantling obsolete US Navy ships for the US Department of Transportation Maritime Administration in circumstances either – (a) where that supply was not made to a part of the armed 10 forces of a NATO member taking part in the common defence effort or to civilian staff accompanying them or (b) where that supply was not made to a part of the armed forces of a NATO member stationed in or visiting the United 15 Kingdom or to civilian staff accompanying such forces?”