While reading up on some WW II history I ran across an article in a 1939 issue of 'Harper's' where an author stated that if Hitler attacked France or Russia that Germany would be destroyed. The author went into rather great detail and analyzed lessons learned from the 'Great War' to make his points.

It was sort of weird and made me wonder if Hitler had paid attention to what was in the article how different history would have been.

The author used a quote "Those who causes fear in others have many to fear" without attritubition as if anyone reading the article would be aware of this.

I am unable to find the orgin of this quote. Has anyone else ever heard this and/or know the source?