That sounds like a decision Quaritch would make, not Selfridge. As the movie indicates, Selfridge wants there to be a truce between the Na'vi and the humans. He doesn't want open conflict.

Quaritch, on the other hand, just doesn't care. He thinks of the Na'vi as just simple, savage, humanoid beasts that happen to walk and talk, so I'm assuming his rationality behind killing them is that they're all just animals.

I think that's referring to the happenings in the actual film rather than with Sylwanin. The marines killed them because, quite simply, they are unintelligent, bloodthirsty excuses for lifeforms who enjoy killing to the point they'd to it as a job against people who have done nothing against them.

I have not read the script nor seen the extra footage.

However, even given what we see in the theatrical version, I think the RDA attack on the Na'vi and Tree of Souls was understandable.

Lets look at situation:
The RDA point of view
The Na'vi are massing in numbers not long after hometree is destroyed. Why would the Na'vi mass unless they intended to attack. I think nit is quite reasonable for the RDA to believe that an attack was imminent, especially considering the damage they had just caused.

The Na'vi point of view
In his speech Jake says that the Na'vi were going to send the Skypeople a lesson. So on that basis, the RDA's fears appear to be completely founded. When i heard Jake's speech, I assumed he intended to attack RDA properly in some sort of way, perhaps taking lives in the process. Theat assumption may or may not be correct, but considering the RDA took many lives at hometree, the war had effectively begun.


So with the Na'vi massing for a potential attack what are the options?

1. Negotiate
The RDA could grovel forgiveness on their hands and knees. It would take a lot of compromises, but Selfridge may be willing to take that. From the Theatrical version, it is not really clear if anyone regards this option as desireable or feasible.

2. Fight
If you are confident in destroying the enemy with minimal casualties to yourself, then war is an option. Whatever else Quaritch lacks, it's not confidence.

In the end both fight and negotiate are both valid options. The option that is taken depends more on who has the most control; the warrior or the merchant.

Except that he had lost control and that's why things ended badly for him. Even Quaritch had completely lost sight of what his actual JOB was over revenge. In the end the marines still made the only aggressive move, not the Na'vi, so deserved every one of them that got killed and more.

I don't disagree with you. What you say makes sense.

In fact, I wasn't looking at the question on a moral level; i.e. was the RDA right or wrong to do what they did?

I was considering it more from a logical perspective. Did it make sense for the RDA to attack the Na'vi as a means to resolve the conflict with the knowledge at their disposal?

I think from a strategic perspective it did make sense. Especially if you are the sort of person who appreciates strength through military might like Quaritch.

But even if he won, it is possible that Quaritch may not have got everything his own way. It is well possible he would have been sacked for the action he took. We know that there was a reluctance to use force against the Na'vi through Selfridge and the scientisits and this attidtude may have been reflected back on Earth, even with the need for unobtanium. But from what I see in the theatrical version, it is difficult to know whether Quaritch would be treated like a hero or a criminal.

But from a purely military point of you, I believe the course of action was valid. But that doesn't mean it was the right or the best decision.

To me, it seemed like Quaritch (in the theatrical) strived to kill Jake because Jake was the cause of everything that happened after destruction of the trees of voices.

The way I figure it, Quaritch assumed that even though he had completely failed his original intention to destroy the Tree of Souls, he thought that if he killed Jake, the leadership would be gone from the Na'vi forces, and the RDA would have a much better chance of regrouping at Hell's Gate to attack again (assuming there were still many Samsons unused back at base). In this theory, we could say Quaritch wasn't only thinking about himself, but rather of the RDA's control over Pandora.

...Plus he was friggin' angry that his shuttle was destroyed. :P

Yeah I'd say he was just pissed at him. It's much more human-alike to just revenge without thinking :P