We'll always have Paris (a work in progress)

I understand the writers of Casablanca prepared two endings to climax the movie's boy-gets-girl, boy-loses-girl, boy-gets-girl-back (and in fact never really lost her heart) chronology.

In one version, Rick and Ilsa board the Lisbon-bound DC-3 leaving Isla's husband, Victor Laslow behind, with no explanation. That ending satisfies our urge to see them together because we know Rick and Ilsa love each other and want them to live happily ever after. But, that ending is also dissatisfying because it offers no real closure for Victor (who has done nothing wrong). And, it forces Rick and Ilsa to act contrary to the character traits that brought them together in the first instance when she thought Victor was dead, and he thought he was just lucky to meet an unattached woman.

In the alternative version, Victor and Ilsa fly off to Lisbon, at Rick's insistence. To persuade Ilsa to board the plane with Victor, Rick argues, ". . . If that plane leaves the ground and you're not with him, you'll regret it. Maybe not today. Maybe not tomorrow, but soon and for the rest of your life."

Ilsa asks, "But what about us," and Rick answers, "We'll always have Paris. We didn't have, we, we lost it until you came to Casablanca. We got it back last night."

Ilsa adds, yes, we got it back last night "when I said I would never leave you."

Rick responds, "And you never will."

While it's painful to see Rick and Ilsa denied the enjoyment of their true affections, it is very moving to know that those affections were genuine.

And, Rick's willingness to send her away with Victor rather than find a way to satisfy his own desires confirms his character, the character that drew her to him in the first place. Maintaining his character insured the longevity of their mutual affections, though it denied them outward expression at that moment (in today's film world, it spells sequel).

I've read that up to the final day of filming, no one knew which ending would be used, but that immediately after they shot the version where Ilsa leaves with Victor, there was no disagreement, there was no need to shoot the alternative; it was a wrap.