Angell's argument was more along the lines that war cannot be strictly justified by economic, financial, or security incentives: "(2) War is not impossible, and no responsible Pacifist ever said it was; it is not the likelihood of war which is the illusion, but its benefits." [^1]

His point was that economic interdependence in the current age(1910-1860) meant that changing the international order by force of arms would not lead to a more favorable outcome for the aggressor. In fact, quite the opposite. The aggressor's economy would be wrecked even in victory no matter the length of the war. Economic isolation from world trade and credit would be devastating.

If he was claiming that war was impossible would he bother to write a book arguing that the benefits of war were not commensurate with the cost? The entire reason he wrote the book was to dissuade 'militarists' and stop the buildup of military potential that began with the dreadnought race and germany's more aggressive wilhelm foreign policy. The book was almost directly aimed at a german audience as a result.

[^1]: http://www.gutenberg.org/files/38535/38535-h/38535-h.htm#Pag...