Aside from the fact that these events (or perhaps events just like them but more horrible ) took place, this film could not be more compelling.
It is filled with first rate performances (some only in cameo, but all of them fully drawn and realized). This is perhaps among the best ensemble film work done by Lee Grant, Faye Dunnaway, Julie Harris, and a host of others. Tension builds with unrelenting force as the story shifts back and forth between The "damned" St. Louis, and Havana where "conscience" in the persons of a father and a leader of the Jewish agency (Ben Gazarra in a meaty role) attempt, unsuccessfully, to plead, then shame, then bully Cuban politicians into honoring the visas issued to the jewish passengers.
We watch as this tension takes its toll on so many of the passengers. We watch as the largely Nazi crew commits their small tortures upon the passengers. We know, as do the passengers and the Captain (Masterfully played by Max Von Sydow) what awaits them should they be forced to return to Germany. The fact that the entire voyage is a perverted Nazi publicity stunt ("See, no one wants them!") is driven home when both the United States and Canada refuse permission to enter their waters....
No spoiler here - you will have to watch the film to see their endings. The performances will haunt you. The set pieces (The entire masked - ball sequence for example) will haunt you. The soundtrack is evocative of europe in days gone by, and the beautiful theme, restated by a variety of instuments and in increasing earnestness, ties the many stories of this large ensemble cast into one coherent experience for the audience.
This is, to many, a mere footnote to history, the plight of these people. But watch and see if you don't feel the largeness of their fear. The impotence of their hopelessness. This underappreciated film has much to teach us that cannot be found in history books.
My only regret is - no widescreen edition. This film begs for it.