Although the final sequence of “Casablanca” puts a neat little bow on the love triangle, its fate is determined during the classic “La Marseillaise” scene earlier in the film. In it, a group of Nazi soldiers gather around the piano at Rick’s Cafe Americain for a full-throated rendition of “Die Wacht am Rhein,” a patriotic German song, much to the distaste of the other patrons. With a steely-eyed fury, Laszlo promptly begins singing the French national anthem, La Marseillaise, encouraging Rick’s band to play and the rest of the assembled refugees to defiantly sing along with them. Before long, they have completely drowned out the German soldiers — a small but emotionally powerful victory. It’s also a sequence that provides insight into the relationship between Laszlo and Ilsa, thanks to the strong performances from both. 

He walks purposefully towards the band, stepping in smoothly to take charge of the situation, even though this is Rick’s bar and thus his problem to handle. Rick gives a nod for the band to follow Laszlo, which serves as both a tacit acknowledgment of Rick’s politics as well as an indication of the ultimate trajectory of this love triangle. As Ilsa watches Laszlo in this moment, eyes shining and face beaming, it’s like she’s looking into the sun. She and Rick are the star-crossed lovers of this piece, but her feelings for Laszlo, full of pride and admiration and love, are equally undeniable. There is a reason she fell in love with this man, and a reason she gets on the plane with him. None of that would land without Henreid’s performance, which is charming and commanding without stepping on the toes of the lead romantic duo.

“Casablanca” couldn’t exist without the very specific energies of Humphrey Bogart and Ingrid Bergman – their romance is what has captivated audiences for 80 years, after all. But it also owes a massive debt of gratitude to its strong supporting performances from a large ensemble cast. Peter Lorre, Conrad Veidt, even the extras who play stranded refugees all bring something special and unique to the proceedings. But it’s fair to say that no one in “Casablanca” was operating in a more tenuous position than Paul Henreid as Victor Laszlo, walking a tightrope upon which a misstep either way could have sent the film crashing down.