The other night in the pre-war news commentary, someone was talking about the way that wars tend not to unfold as plans, and they quoted Caesar's remark about crossing the Rubicon, "...the die is cast." The speaker was interpreting this as in "a roll of the dice."

I had thought that the phrase "the die is cast" referred to metal work, i.e. metal poured into a form and allowed to cool. Which is correct?