let me put it another way. the white paper says, and Mr Salmond presumably endorses this if he didn't write it himself:-
An independent Scotland would seek an agreement on getting rid of Trident within the first term of the first Scottish parliament following independence. It would also apply to join Nato.
http://www.theguardian.com/politics/2013/nov/26/scottish-government-publishes-white-paper-on-independence-politics-live-blog#block-529487ede4b079ca881a4b79
"seek an agreement" is clearly an aspiration, particularly since there's also an intent to join NATO. Thus this is a recognition that at this time, Scotland is the only available parking lot. This also assumes that the SNP are the governing party within the first term of the Scottish parliament, which they might not be - I mean, can you trust your fellow members of the electorate to do the right thing?