It really holds up well. What may have been intended as a Cold War parable--peaceful suburbanites=USA/ruthless gangsters=USSR--can be read in the context of the Global War on Terror just as readily. Bogart could be a Bin Laden-type. The complacent surburbanites are just as apt today. Message: you can't rely on the authorities alone to defeat terror, suburbanites must think for themselves. Frederic March actually stands up not only to Bogart, but also to the police, in order to defeat the desperatdoes.
In the 50s it meant standing up to Joe McCarthy and Stalin both. Today, it means standing up to George W. Bush as well as Osama Bin Laden.
It's not called "Hollywood's Golden Age" for nothing...