Uncharted 2 is not about honor among thieves or no honor among thieves. You are merely "among thieves," left to make up your own mind about the matter.
The title of Uncharted 2: Among Thieves, of course, is a play on two well known phrases “Honor among thieves” and “No honor among thieves.” The first is based on the assumption that because both parties are thieves that they are in this together against the law, while the latter is based on the idea that since these individuals are both thieves that they will act out of self interest regardless of any personal connections to one another. Both phrases are well known and have been used a lot in fiction. However, each of these phrases' uses are wholly dependent on what a work is trying to say as a whole.
Uncharted 2 clearly hints at the phrase by putting two of the familiar words that comprise the phrase together. However, by omitting the word ‘honor,’ the title refuses to make a statement one way or the other. The game is not about honor among thieves or no honor among thieves. You are merely "among thieves," left to make up your own mind about the matter.
What is interesting is that the game makes the case for both ideas, not by pitting two sides against one another, but by allowing all the thieves in the story to embody both ideas at different times. Drake is supposedly the hero, but during the planning of the robbery of the Turkish museum, he is more than willing to rip off the as-of-then unknown buyer alongside his fellow thieves Chloe and Flynn. Later in his hotel room with Chloe, the two plan to leave Flynn out in the cold as well. Drake is ultimately the good guy, but here he is not an honorable man. Later on, he makes several stupid decisions based on misguided loyalty and in an effort to play the hero.
Flynn was always planning on double-crossing Drake. He knew the prize that he was after, but he also knew that he could not unlock the key of the lamp. Much like what Drake was planning to do to Flynn, Flynn was also going to use him, then lose him. However, he wasn’t doing it for his own benefit, but on behalf of his employer. He doesn’t betray him, possibly out of loyalty or possibly out of self-preservation. Also, while he is willing to leave Drake for dead in a Turkish prison, he sticks his neck out for Chloe again and again. So. while the game portrays him as a rat bastard, he has his nobler qualities as well.
Then there is Chloe. It is difficult to tell whose side she is on, even if it may be her own. She is willing to betray both the client and Flynn with Drake for the lamp, but then helps both Drake and Sully get into the jungle compound. But as soon as Lazarevic shows up, she turns on them immediately. In Tibet, it is the same song and dance. She helps Drake and later Elena and Jeff, but once they’re cornered, she pulls a gun on them. You could reasonably assume that it is to save her own life, but when Drake comes to rescue her, she chastises him, saying she didn’t want to be rescued.
Much has been made about the triangle between Drake, Elena and Chloe because of how much screen time these characters get, but far more interesting and integral to the themes of the game is the one between Chloe, Drake and Flynn. For most of the game, Flynn is absent from the on-screen action, and for most of her appearances, Chloe is partnered with Drake. But her decision between the two men is more indecisive than Drake’s. It is also not about the men but about what they ultimately represent in her life. She won’t get either of them and quite possibly doesn’t want either of them, but they are the symbols of how she will define herself. Drake is the more upstanding of the two with an eye of “being the bloody hero” and saving the world. Flynn is the down and dirty scoundrel all about keeping his eye on the prize. This is a perfect realization of the dichotomy at hand. One represents the possibility of honor, while the other represents the possibility of having none. As stated before, both men straddle the line, but it is in which direction they choose to face that matters.
As much as the game’s presentation of the events try to get us to see Drake’s choice as a difficult one, there really isn’t a choice at all. As soon as Elena shows up, it’s obvious which woman Drake will go for in the end. He shares a history with both of them, but we’ve only witnessed his relationship with Elena. We’ve been told about his one with Chloe. Plus, at the point in the game, Chloe is questioning Drake’s every decision when he tries to be a better man. They are drifting apart because they no longer see the world quite the same way.
Chloe doesn’t want to see Drake hurt or killed, but he in turn is making it hard for her. She is at her own crossroads. Does she rise up and be the better woman or does she succumb to her own desire for the prize? It’s like Chloe can only take so much of this new Drake before she reverts to her old ways and goes back to Flynn’s team. But as soon as Drake shows up at the mountain temple when they’re alone, she switches teams again and follows him. Her indecisiveness means that she is the only one who has betrayed everyone in the story at some point or another. Meanwhile, she is the only person not to be betrayed by anyone. Even after Lazarevic has had enough of her antics, Flynn still sticks up for her.
In the end, she doesn’t make any choice at all. Lazarevic forces her hand. She goes to Drake, but in the end, she chastises him and can’t take his “nobility.” She doesn’t give Drake the chance to tell her that he has made a choice because she didn’t get to make her own. While both men are out of her reach, her choice about her own life at the time of the credits is still up in the air.
It’s a pity that Chloe is not given center stage more often in the game because her story really is the story of the game. The battles between the different philosophies of the criminal are summed up by her situation. She is literally deciding between two thieves and is at the center of the entire debacle. If you follow Drake’s story, it reaffirms that loyalty and righteousness are the true path. If you follow Flynn’s story. it becomes a cautionary tale of who you should trust. The former is about honor among thieves and the latter demonstrates that there is no honor among thieves. But Uncharted 2 is about neither of these ideas. The whole problem is caused and maintained by Drake’s foolishness and planned betrayal. Meanwhile, Flynn spends most of the time doing his best to keep Chloe and himself alive in a terrible situation. The game is about the struggle between these two competing ideas: honor or no honor. Only Chloe, by never getting to make a choice or having her story resolved is merely "Among Thieves."