On a completely different tack – everyone goes to a massage parlor.
"I say we take off and nuke the… "
Oh, that’s right - Sigourney Weaver’s character dies in Avatar.
Maybe they have access to “independently-targeting particle beam phalanxes?” 
Actually, the analogy is a good one…soon, the Chinese will be opening (possibly) the largest copper mine in the world-in Afghanistan.
Then the US public will be wondering why American troops (paid with money borrowed from China) are fighting to protect a Chinese-owned business, in a country nobody cares about.
The Navi did take over the body’s of the released humans - and are now planning to invade earth using them as the forward guard.
I think the happy ending would be that the mining company realizes that instead of mining the huge quantity of unobtanium and flooding the market with it thus reducing its market value, they actually support the Navi and keep it out of the marketplace, thereby keeping their current mining operations of unobtanium extremely valuable.
The flaw in their General’s plan is that one of the aliens is bound to turn the tables on 'em after falling for plucky reporter Lois Lane.
According to the wiki Unobtanium is a superconductor with bizarre magnetic properties and is used to contain the mater/anti-mater explosions that make cheap space travel possible, as well as near limitless planet based power generation.
On a side note, Afghanistan is a crap analogy because the US went in as a government entity to begin with and it was never about resources. A better analogy would be the Opium Wars of the nineteenth century fought largely due to the difficulties the East India Company was having in obtaining materials from China. You could make a case that those wars were fought over tea!
The Na’vi are screwed. Unobtanium is just too ridiculously valuable.
You vicious monster.
Promoting 3D. How could you?
Since there’s basically science/magic revealed at the end by human dude being reborn in his avatar body “plausible” is stretched a bit.
The higher technology will always win in the end, which is why the Earthlings are screwed.
What, you weren’t assuming that the Na’vi were the dominant beings on Pandora, were you? They don’t have high technology because they are the technology. Or at least, one facet of it. Any sentient being with the capability of levitating whole mountains easily has the capability to swat down a few warships. The Na’vi, and the unobtainium, and the floating mountains, all exist because Eywa created them.
Much of this was cut from the theatrical release, but the background set-up includes the fact that Earth has completely ruined its own ecology, and that what they learn of Pandora’s ecology is basically the only hope for fixing Earth’s mess. Which was the entire reason that the Avatar program was still funded.
Additionally, the logistics of carrying out a nuke-'em-'till-they-glow war with multiyear transit times would seem prohibitive. No matter how profitable unobtanium is.
But I think that Chronos is right: Eywa is a sufficiently-advanced technology that the humans have no idea of what they’re dealing with. And its been rumored that the other moons of the Polyphemous have similar ecosystems…
I routinely hate all humanity on a daily basis.
Then I have coffee.
Well to be fair, Avatar is one case where it was used pretty effectively.
The failure of the mining mission increases the market price of unobtanium. Soon afterwards, research into artificially produced unobtanium pays off, and means to mass-produce the stuff are developed. (A civilization which can produce antimatter by the ton can synthesize anything made of matter. Don’t give me this ‘impossible to synthesize’ bullshit.) Future missions to Pandora are conducted for biological and cultural research and funded largely by wealthy ecotourists and commercial broadcasting of nature documentaries. The biological wealth of Pandora proves to be vastly more valuable than any mineral wealth in the long term.
Humans don’t need to wipe out the Na’avi to mine Unobtanium. There was just a big deposit under the Home Tree (which wasn’t a coincidence, the Home Trees need it) that was close to the human base, and it was cheaper to flatten the Home Tree and mine there than to mine in any of the other 9,999,999 unobtanium deposits on Pandora.
The battle we saw at the end of the movie? That wasn’t half a planet attacking. That was all the Na’avi within a few week’s travel. It was tens of thousands of Na’avi.
The next time the humans set up a mining colony, they can just do it on some other part of the planet, thousands of miles from the first colony, and start over. Like, if Aliens land in America in 1200 AD and start mining, and the locals get annoyed and massacre them. They Aliens don’t need to wipe out humanity to continue mining, they just move to Australia and they refrain from doing the annoying things they were doing back in America, like massacring the locals and destroying their homes and defiling their sacred places. They don’t even have to move to Australia, they just need to move a couple hundred miles away on the other side of a desert or mountain range, and none of the local tribes will have heard anything about the problems at the first site.
This is how the Pilgrims were able to establish a peaceful farming community at Plymouth Rock, despite their fellow Europeans slaughtering and enslaving the indians in Mexico, the Carribean and South America.
Of course, the Indians in America weren’t connected to a planet-wide biological internet.
The humans in Avatar want unobtanium, they might even need unobtanium to avoid human extinction. There is absolutely no evidence that the cheapest way to get unobtanium is to massacre the locals. See, Pandora is what we scientists call a “planet”. I know that science fiction has led you to believe that a planet has roughly the size and population of a small town, but in reality planets are a lot bigger. How many nuclear bombs are you going to drop on a population of hunter-gathererers spread out over a whole planet? The limiting factor is how much mining equipment can be sent to Pandora. Sending troops and weapons is counterproductive because they take up space on your hyperexpensive space ship that could be filled with miners and mining equipment.
The goal is to ship unobtanium back to Earth. Cheapest way to do that is mine and leave the natives alone.
Pandora is not a planet, Mr Scientist-guy. It’s a moon. 
Incidentally, the moon in the movie shares the same name as the real life moon Pandora, which orbits Saturn and was discovered by one of the Voyager Space craft back in 1980
Best answer. Yours and Lemur866’s.
Alternatively, the humans then return with a single ship carrying frat boys. They are absorbed by the Collective, and Pandora is destroyed by fierce partying and fornicating within a week.
Um, yeah, about that…
Or someone else. Even in universe I understand it’s speculated that the Na’vi are artificial; they look too much like humans, and in various ways don’t fit with the rest of the life forms there. Which leads to two conclusions; there is or was a very advanced species that may well have an interest in the welfare of the Na’vi; and they know where we live. Destroy the Na’vi and/or Eywa, and the Pandoraverse version of the First Ones may well show up sooner or later looking to eradicate the vermin that ruined their experiment.