It should be the aim of grand strategy to discover and pierce the Achilles' heel of the opposing government's power to make war. Strategy, in turn, should seek to penetrate a joint in the harness of the opposing forces. To apply one's strength where the opponent is strong weakens oneself disproportionately to the effect attained. To strike with strong effect, one must strike at weakness.
B. H. Liddell HartI used to think that the causes of war were predominantly economic. I came to think that they were more psychological. I am now coming to think that they are decisively "personal," arising from the defects and ambitions of those who have the power to influence the currents of nations.
B. H. Liddell Hart