London Has Fallen/伦敦陷落

Its storyline is kind of like "Olympus Has Fallen" or "White House Down", but come on, can you find some smarter writer to make the story more logical? How can there be some UN-level terrorist organization to murder all the governments presidents while gets defeated by some bodyguard alone? Can there be some more convincing explanation to make sense?

Performance impression:
Director: Babak Najafi
Stars: Gerard Butler, Aaron Eckhart, Morgan Freeman