What I got mainly from National Anthem was an exploration of the twisted logic that our leaders are responsible for the actions of others if they don't do whatever is required to stop them. The PM was forced to follow through with the act after the public said they would blame him for the Princess's death if he didn't.
It made me think about how this happens in today's society; with some arguments made about how we are responsible for Islamic terrorism because we treat their countries badly. Or how during the riots last year the government was accused for being 'responsible' because of it's policies.
Actually the final straw, if I recall, was his aide telling him they couldn't guarantee his safety of that of his family if he didn't commit the act in question with the irony being the princess was released hours earlier and they had not get the DNA test result back indicating it was the artist's finger, not one of the princess's digits. So it was a case of not enough of the right information but just enough of the wrong kind to make an elected official do a disgusting act in order to save others and appease the public's demands. Also the fact that it all could have been avoided had their been fewer people following the news coverage in pubs, hospitals and in their homes and had instead been outside and seen the princess wandering for the several hours she was free but drugged, stumbling through empty streets because the focus had went from finding her to making sure he fulfilled his part of the deal with the pig.