STYROFOAM

In answer to a question about VBAC:

(when the doctor says it was a good thing they did another cesarean, because the scar looked thin)

If the scar has held up until and during labor it has most probably proven its integrity. This was discussed in my first book Silent Knife in some detail. Also, let us realize that the strength of something does not depend on its thickness.  Styrofoam, as one example, is very thick, but can be cut or torn apart very easily, while silk is thin but very strong.