In that case, yes, you would be correct to say that: "No, not so fast". Of course, I think you summed it up best, Lena, when you pointed out the pairing..."so..as" is incorrect, and "as...as" is correct.
The comparison is to the previous statement. She was compared to the kind of beauty that causes men to go to war. She was THAT beautiful, in comparison. Not less beautiful, or more beautiful, but just as beautiful as what caused the war. You're right in that it doesn't have to be the past, too. It can be in the presentYet I think the word “that” in “She was that beautiful” does not denote any comparison either. Actually her beauty is not compared to anything![]()