A commenter on Reddit:

“For years after Casino Royale came out, the most common gripe about the movie was the last 20 minutes and how much it dragged compared to the rest of the film.

“The whole point of the film is the last 20 minutes. Everything that precedes that in Casino Royale is just Bond on the clock:

• International terrorists.
• Guy who’s financing them.
• Find a way to stop him from making a ridiculous amount of money off a short-sell.
• Follow him to wherever he’s going next.
• Have a run-in with some very unhappy bad guys armed with a machete.
• Win the poker game.
• Get rescued (huh?) when the Evil Banker kidnaps you and Vesper.
• Keep M happy despite a few fuck-ups along the way.

“If the movie ends there, it’s a fine but unremarkable action movie. … The whole point of Casino Royale is to get Bond to the last 20 minutes and then shatter him. So now Vesper’s in the picture and Bond starts to have those first niggling thoughts about what his life might have been like outside government service. … It’s not too late for him to leave MI:6 and do something else if she’ll have him. The last gasp of the old Bond is in the torture scene. Remove Vesper from it entirely and Bond’s modus operandi is fairly straightforward: Torture me, don’t torture me, kill me, don’t kill me … you’re not getting the money either way so fuck you, who cares. Up yours, frogface. The only point at which he evinces actual concern over the proceedings is when he hears Vesper begin to scream. Now he has a reason to care about the outcome, but he passes into unconsciousness without knowing that Vesper’s already cut the deal that saves his life.

“And that’s why Vesper has to die. Past the torture scene, there’s no way to salvage the relationship between them (even though they’re not even in a relationship at that point anyway). She’s handed over the money, extracted a promise to keep Bond alive, and sold out her country for the benefit of a man she believes is going to die if she doesn’t. Fleming knew what he was on about. “Vesper Lynd” is an intentional and close relative to “West Berlin,” the unhappy city with such divided loyalties during the Cold War and no way to fully resolve that division.

“If she lives, the relationship is over, because Bond will never fully trust her again. The small moment after M calls wanting to know what the hell happened to the money is instructive; instantaneous rage, how-dare-she, I-got-played. Alternate-universe Casino Royale is where he rescues her from drowning but writes off the entire experience as “Bitches, man!” He asks himself what the hell he was expecting and go back to doing what he’s always done (albeit in a fouler mood than before). He learns nothing, doesn’t change, and there’s basically no character development of any kind in the film.

If she dies … well, that was the ending we saw.

“Casino Royale is the story of where James Bond begins as a character, but he’s clearly been knocking around the business for a while before we enter the narrative. So Bond doesn’t start with the job; Bond starts when the love of his life shatters him for a completely understandable and even somewhat honorable reason and then dies for it. That is the origin story of the empty suit and the dead eyes and the reliance on alcohol just to get through the day. The nihilism and descent into sociopathy comes from his realization of just how trapped Vesper was, and how she felt the only way to expunge the guilt and shame of what she’d done was to take it to the grave with her.

“And then in Quantum of Solace he finds out that she died for nothing.”

Full discussion https://np.reddit.com/r/dataisbeautiful/comments/3qenef/daniel_craigs_james_bond_has_drunk_the_most/cwet3si?context=5