> economic interdependence deserves the bulk of the credit for this relative peace.

That was the thesis of a book called The Great Illusion

https://en.wikipedia.org/wiki/The_Great_Illusion

The book argued a European war was very unlikely.

the economic interdependence between industrial countries would be "the real guarantor of the good behavior of one state to another", as it meant that war would be economically harmful to all the countries involved.

The book was published, to great acclaim, in... 1909.