Few figures on the contemporary scene are as controversial as Edward Snowden, the former intelligence officer who, in 2013, revealed the existence of a secret National Security Agency program for mass data collection that he considered abusive.

Champion of individual rights against an intrusive government or a traitor to his country? Opinions about Snowden vary between these two extremes, but also probably occupy every square inch of the wide philosophical and political territory dividing them.

Riding into this ongoing fray comes left-wing stalwart Oliver Stone. As director and co-writer (with Kieran Fitzgerald) of “Snowden” (Open Road), Stone serves up an interesting screen biography that eventually proves excessively long and one-sided.

Holed up in a Hong Kong hotel on the eve of his epochal leak, Snowden (Joseph Gordon-Levitt) recalls the events of his life, beginning with his service in the Army, to documentary filmmaker Laura Poitras (Melissa Leo). Between the flashbacks that follow, he also strategizes with the two principal reporters, Glenn Greenwald (Zachary Quinto) and Ewen MacAskill (Tom Wilkinson), working to publish the documents he’s stolen.

Stone initially presents his protagonist as a conscientious man pulled in different directions by his loyalty to the government, his larger sense of duty and his love for his girlfriend, Lindsay Mills (Shailene Woodley). Once Snowden determines his course of action, however, a hero-worshipping tone takes hold to a degree that mars the film’s effectiveness.

If the script is historically accurate, the intelligence community does have some life-endangering, morally indefensible actions to answer for. But the larger question “Snowden” raises — how to strike the proper balance between security and privacy — remains a prudential judgment about which viewers of faith are free to disagree.

The film contains a graphic scene of non-marital sexual activity, images of upper female nudity as well as partial nudity in a strip club, a few uses of profanity and frequent rough and crude language. (A-III, R)