[Spoilers, by the way.]
As a general rule, American movies are about Americans. There are exceptions,* but mostly they're about Americans. So The Darkest Hour, which is set in Moscow, of course centers around a couple of Americans. But something interesting happens that you might not expect.
The movie is so focused on them that you might not even notice.
They're not the heroes. They bump into the heroes, they play messenger between heroes when one dies but has information and technology that the others need, they hide behind the heroes and even occasionally aid them, but they're not the heroes.
If this were Red Dawn then the ones shouting, "Wolverines!" would be the group of Russians that saved the Americans' asses partway through and then kept on saving their asses as the movie went on. It was even made very clear, this was their home and they were going to defend it. "I can go no further, for I have Moscow at my back," a hero said to the Americans as they ran away in a nuclear submarine that belonged to still more Russians.
And as they ran away the heroes gave the Americans a job to do. Not a hero's job, a messenger's job. "Today we learned how to fight, go and teach the others what we know." Note the "we" in there. It could include the Americans, it might not, but it distinctly isn't, "Today you learned how to fight, go and teach the others what you know."
Remember that guy in Independence Day who was sitting at a table tapping out in Morse code how to blow up the alien ships (wait for them to deploy the big fucking gun and then send an explosive right up its barrel)? You probably don't. Because that person wasn't one of the heroes. He was just a messenger. That's what the Americans are.
The Americans do not discover that Faraday cages can protect them from detection, this in spite of finding something that would otherwise light up like a beacon to the aliens inside of a Faraday cage. No, a Russian discovered that and converted his entire apartment to a Faraday cage, put the light on to attract other survivors to him, and built a fucking weapon to defeat the aliens in his home in between doing all that other stuff.
He's hero number one, the genius inventor who discovers the aliens' weakness. He dies for two reasons: first, a member of the American's group (an Australian herself) doesn't listen to a Russian who, though younger, proves smarter than she is. When an alien shows up rather than follow the person who knows what she's doing (Vika, the Russian) she instead leads the alien right back to the protected room which, as Vika predicted, they didn't have time to do. Specifically the door can't be closed behind them in time, the Faraday cage is breached, and the genius inventor is now face to face with an invisible alien. To protect the survivors he grabs prototype weapon number one and uses it on the alien. It works, but only stuns the alien. Then it shorts, preventing him from firing again. That shorting is the second reason he dies.
He knew he didn't have enough power, but could only work with what he had.
His sacrifice buys time to save the remaining members of the group who grab prototype two and meet up with Vika and they all head toward the submarine (Vika previously translated a repeating signal in Russian announcing the location of the sub and how long it would stay there.)
With hero one gone the Americans plus Vika seem pretty well screwed. They have prototype number two, but it only stuns the aliens and knocks out their shielding. Conventional weapons are needed to finish the job.
As they run like hell they eventually are saved by the real heroes. The ones who are not willing to abandon their home to alien invaders and are prepared to stand and fight. Without the inventor's weapon (a microwave gun, don't ask) they're only able to wound the aliens but they've none the less done quite well for themselves and are there to defend any survivors, Americans included, that they should find.
They too have made their headquarters into a Faraday cage.
When they learn of the sub they have no intention of going to it because unlike the Americans they aren't going to run away. When the Americans, and Vika, decide to go to the sub on their own a small detachment, including the heroes' leader, decides to give them escort on what would otherwise be a suicide mission. (The leader makes sure to delegate responsibility before he leaves, he's not going to leave his people leaderless.)
And so they go, shit happens, they lose another American bringing their compliment down to two and they then get separated from one of those. Along the way they all notice the aliens operations and while the Americans are baffled the Russians have been able to deduce what's going on (the aliens are there to mine the earth, killing off the indigenous population just makes it easier.)
When they reach the sub the sub's acting commander (the actual captain has died) wants to leave on schedule but is managed to be convinced to stay long enough for the others to get the separated American. (The fact that she sent up a literal flare helps with this, as they now know where to look.) It is then that the Russians on the submarine are able to build a second microwave gun and improve on dead-Russian's design because of greater resources.
The commander stays with the sub, the Russians staying in Moscow escort the remaining American to find the missing American, Vika is to stay behind because of her age.
The remaining American delivers his last bit of information from the dead-Russian inventor, a way to make the mircowave gun do more than it otherwise would by getting aliens in close proximity, connecting them electrically, and then firing on them. In this case getting them over water. And so water is spilled for a trap.
This fails. Utterly. The American's plan is for shit because the aliens aren't stupid enough to go over the water and into the trap. Enter Vika with Molotov cocktails. The plan is saved when to avoid the fire the aliens inch over the water and enter the trap. Bang, bang, bang no more aliens there. (Many more throughout the rest of Moscow but small victories.)
The two remaining Americans reunite and with Vika make it back to the sub where they separate from the Russians who are staying in Moscow. The dialogue I told you about before is given.
The Americans and Russians on the sub learn that around the world the extremely depleted human population is fighting back and gaining ground. In the words of one of the Moscow bound Russians, the extermination is over, the war has begun.
And that's the plot of the entire movie. Notice anything?
The Americans accomplish almost nothing on their own. They act as, basically, messengers and delivery people.
The Americans don't make the microwave gun, a Russian does.
The Americans don't duplicate the microwave gun. Russians do.
The Americans don't improve the microwave gun. Russians do.
With, I think, all of one exception, the Americans don't fight off the aliens, the Russians do.
The trap that an American thought up, which was only thought up because of information he got from a Russian, didn't work until Vika, a Russian, made it work by forcing the enemy into it at great risk to herself.
The Americans aren't even responsible for their own getaway, the Russians are.
The Americans are not the heroes. They're the people who either hide behind or give support to the heroes. They're the foreign sidekicks. You might miss that fact because the movie focuses on them, but that's the way it is. They don't accomplish anything, instead they help other people accomplish everything.
They deliver the radio which is still working and tuned to the right frequency to pick up on the sub's signal to the inventor and Vika. They deliver the microwave gun to the sub. They deliver the information about getting more bang for your battery by getting multiple aliens together in a state where they can be electrically connected to the people who can actually use that information.
They deliver a couple (maybe a few) bits of information and one object. That's all they accomplish. (And they kill that one alien. Far fewer than the Russians do.) Everything else is left to the real heroes of the movie: the Russians.
You know how every bad movie set in medieval times has a Chinese sidekick to provide the kung fu and gunpowder? The Americans in this movie are that Chinese sidekick without the kung fu and gunpowder. They're sidekicks, and not very impressive ones at that.
This is, for me at least, a different direction for movies to take and, honestly, I like it. First off, if you're going to have Americans in Moscow for the alien invasion you should not under any circumstances have them save the world. Moscow is full of people and the odds that some random foreigners are going to be the ones best equipped to solve the problem are exceedingly low.
But given that you've still got a choice of focus. Now I know that it really wasn't about deciding that maybe this once the sidekicks deserved to be the story's focus but instead a desire to have the Americans be the story's focus, but even so I like giving the focus to the non-heroes.
There's something nice about having the movie be centered on not the hero who saves the day but rather the people who hide behind them. It wouldn't do to have all movies focus on such people, but with almost every movie focused on the heroes it's good to have a movie focus on someone else for a change.
They're support characters, needy characters, characters who need an escort because without it they'll be dead, and they have stories too.
* For example, The Three Musketeers:
The Three Musketeers: Part 1 and Part 2, 1911 (Don't know if these still exist.)
The Three Musketeers, 1914 (ditto)
The Three Musketeers, 1916 (I think the link goes to the right place but there's only one in stock and it has very little info.)
The Three Musketeers, 1921
The Iron Mask, 1929
The Three Musketeers, 1933 (John Wayne version)
The Three Musketeers, 1935
The Three Musketeers, 1939 (comedy)
The Man in the Iron Mask 1939
The Three Musketeers, 1948 (Gene Kelly and Lana Turner version)
The Two Mouseketeers, 1952 (Tom and Jerry version. Honestly these four things are just annoying to track down. No links for them.)
Lady in the Iron Mask, 1952 (Amazon does not have this either.)
At Sword's Point, 1952 (The protagonists are the children of the original Musketeers)
Touché, Pussy Cat!, 1954 (sequel to the Tom and Jerry version above)
Tom and Chérie, 1955 (Third of the Tom and Jerry cartoons)
Royal Cat Nap 1958 (Fourth and final installment of the Tom and Jerry version)
The Three Musketeers, 1969 (Christopher Walken version which has never been released on any form of video)
The Three Musketeers, 1973 and The Four Musketeers, 1974 (I grew up on these, and the 1993 version, but these first. Raquel Welch is my mother's favorite Constance.)
The Return of the Musketeers, 1989 (Sequel to The Three Musketeers, 1973 and The Four Musketeers, 1974)
The Three Musketeers 1992 (Animated. If you want it on DVD you need to buy a three movie pack.)
Ring of the Musketeers, 1992 (A movie about modern day descendants of the Musketeers that includes John Rhys-Davies and David Hasselhoff, what could possibly go wrong?)
The Three Musketeers, 1993 (Charlie Sheen, Kiefer Sutherland, Oliver Platt, Chris O'Donnell, Tim Curry, and Gabrielle Anwar version)
The Man in the Iron Mask, 1998 (Jeremy Irons is awesome in this, for the record)
The Man in the Iron Mask/The Mask of Dumas, 1998
The Musketeer, 2001 (Have you ever wanted to watch a painfully long and painfully dull aerial fight taking place on wooden ladders? Then this is the movie for you! Otherwise, I don't really recommend it.)
Mickey, Donald, Goofy: The Three Musketeers, 2004
La Femme Musketeer, 2004 (John Rhys-Davies again, anyway D'Artagnan's daughter teams up with the sons of the three and attempts to prove that she's as awesome a swordsman as any man, or something like that. It's not as if I've seen all of these.)
Barbie and the Three Musketeers, 2009
The Three Musketeers, 2011 (Airships! That are actually ships, in the air. Not much else to recommend it.)
3 Musketeers, 2011 (Asylum version)