We watched it because of Judi Dench and were not disappointed.
It’s not a great movie but it’s an interesting one and it tells a good story, presenting the dilemma faced by whistle blowers, and often traitors, throughout history.
A truly moral person is an idealist...who acts as ones conscience tells one to act...in this case for the salvation of the world.
Society deems it wrong and treasonous; the idealist knows this but must obey conscience.
Thus, the struggle.
And for the viewer, the question has been posed.