How I felt about it. Since dialogue is sparse and sarcastic, and in British rather than English (languages an ocean apart), the story can be difficult to follow. The selection of camera angles doesn't always help matters. For example, a body is revealed from the perspective of the top of a lamp, rather than the door or hallway, when it would be first seen.
And, there are the unexpected plot twists, requisite in a detective yarn, but not always credible. I count six killings, two of which make sense, while four are dubious.
There is a 'bird', of course, for Caine as Palmer to conquer. This is accomplished after only brief gamesmanship, and soon she has tears in her eyes at his departure. After all, in the make-believe world of spy versus spy, betrayal and death occur on a daily basis. Perhaps two years on a military prison isn't a worse alternative, even if their mushrooms are a dime cheaper by the can.
Smart tough guy Caine, as in Get Carter (1971), is likely to come out on top. But similar to James Bond, he has to go through a lot of trouble to get there. The difference between Bond and Caine is that the latter wears glasses, and must rely upon his wits more than gadgets.
The relationship between Ross and Dolby is more interesting than Palmer's success at flirting or sleuthing. Ross has the upper hand, and Dolby's track record is suspect. But the two are surprisingly alike in terms of personality, and since their cards are kept close to the vest, it's up to the actions of Palmer to reveal which boss holds the wrong hand.
How others will see it. A large (and mostly male) audience relishes detective stories, which this movie more or less is despite Palmer's status as a military spy. Mystery fans will not be disappointed, and will probably figure out who the bad guy is (there's not many suspects to choose from). Now if only the American spies weren't made out to be so blunt, useless, and expendable.