What is the purpose of the flashback to the plane?

Beyond the implication they were intending to nuke a target never described and therefore hardly relevant to the plot, it was seemingly meaningless. I was sorely disappointed with this film. I'm not quite sure why so many recent films are taking the "LOST" approach to story telling: Build a complicated plot through inference and flashbacks, only to end the film abruptly without providing a shred of an explanation as to what happened to the characters we were introduced to, or even the plot of the story in this case. This was a complete waste of a film, as it posed countless concepts without exploring any of them. Pure rubbish, and I actually consider the PA genre my favorite, despite the countless failures the genre has produced.