The absolute and the rest.

I am, in part, a technologist, when in that mode and asked "can I do this" my answers are based on having translated the question into terms of "is it at all possible". The rest of the time I am a pragmatist and a solution provider and in that case I am answering the question in terms of business cases, cost-benefits or having to translate the question from some impenetrable non-technical (generally marketing based) misunderstanding.
When thinking about the political space I do my best to do my thinking in the latter mode, which is why I emitted a Homeric Doh! when I read this piece about the "Wilson Doctrine" by Nick Robinson. Of course no sitting prime minister would tie their hands like that without leaving a suitable loophole.

"But if there was any development of a kind which required a change in the general policy, I would, at such moment as seemed compatible with the security of the country, on my own initiative make a statement to the House about it." &mdash Harold Wilson

How, as a dedicated fan of Yes Prime Minister I didn't think about it in those terms I didn't know.