Finally, a supposedly terrible film that was actually terrible! I mean, yes the action sequences were enjoyable, pacing was decent, and I wouldn't say the acting itself was ever really in question. Still, with a story this idiotic none of that will truly matter. It doesn't take acting gaffes to remind me that the whole thing is fictional when you have a plot this stupendously unrealistic. I mean, this is an action film; I don't expect realism in my plot! Yet still, London Has Fallen manages to exceed expectations so utterly I almost turned it off. If I hadn't been trapped on a plane with very little else catching my attention that would have certainly been its fate.
To briefly validate these harsh words, please understand that the entire plot revolves around the premise that a small, 'undetectable' group of 'terrorists' somehow manages to fully infiltrate every single emergency and government service in London, including the military. Literally every organisation is compromised to such an extent that the single largest gathering of world leaders in decades has zero effective background or spot checks in place. Not only that, but considering the 'assassinations' take place in various (highly contrived) locations, many of which have only been planned for a maximum period of a couple of weeks, this level of infiltration must spread the secret services of most countries, giving access to state leaders personal details and encrypted communication methods.
Except, of course, for the US, whose own intelligence service appears to have been entirely overlooked, despite their President being the ultimate target of the entire plan. Even then – granting this insane setup – you also have to accept that there are no ideological reasons for these hundreds of individuals to die at Gerard Butler's hands. The sole motive for this entire plan is that an arms dealer loses his daughter to an American UAV strike. None of these henchmen can be anything more than guns-for-hire mercenaries, which means you have to add all major inbound port security in the UK into the mix of 'compromised' agencies. Not to mention where the hell they got all those weapons from, or why they have access to seemingly every building in the capital, or where the hell all the civilians have gone.
Speaking of which, and to show it's not just the bad guys who make no logical sense, why would they use the air raid sirens to signal a curfew? Why would this even work? London (or any other major city) isn't exactly well known for people not rioting at the first suggestion of a loss of authority from the police! Plus, why would you not just use the damn radio! Or do these 'terrorists' also have that network fully comprised? I mean, to be fair, at this point why the hell not...