Jack Strong (2014) is a Polish film based on a true story, though like all films based on reality it takes some liberties. Its the Cold War. A Polish Army officer (he's promoted twice in the film so by the end he's a Colonel) Ryszard Kukliński disgusted that most of his fellow officers have no back bone to stand up against the Russians and afraid the Russians will involve Poland in a nuclear war becomes the CIA's best intelligence source in Europe. Whatever the Russians were up to in Europe he warned the Americans about. He's been credited with stopping World War III.
For most of the film is slow paced. No action sequences until near the end when he and his family have to flee to the US after he believes he's been discovered. Then there is a care chase.
The ending is a bit jarring especially if you know the true facts.
The film ends with Kukliński waiting in Washington DC for his older son (according to the English subtites) to pick him up on the anniversary of his younger son's death. Cause of death is not mentioned. His son never makes it as his car is ran off a bridge by a truck. That's not how it actually happened. Both sons did die in mysterious circumstances but not like this. The oldest son was actually on a American university campus when he was run over by am unlicensed truck. A year and a half later, his younger brother vanished from a yacht, on a night when the ocean was calm.
The film does not mention that Ryszard Kukliński died of a stroke in 2004.
Apart from the ending I enjoyed the film.