“It is only one who is thoroughly acquainted with the evils of war that can thoroughly understand the profitable way of carrying it on.”
You cannot wield a tool well until you respect its dangers; clarity about cost is what makes gain possible.
Chapter 2 pauses its cost-listing for a qualification: only one thoroughly acquainted with the evils of war can understand the profitable way of conducting it. The verse gives the chapter its epistemic key — Sun Tzu’s economics are not pessimism but permission. Knowing exactly how campaigns fail is what licenses fighting them well; the novice’s optimism is simply unpriced risk.
Two founders raise for the same expansion. One has written the failure memoir in advance — what a churn spike does to the covenant, which costs are fixed when revenue dips, the month the payroll gets interesting. The other has a deck of upsides. The first negotiates a slightly worse valuation with better covenants and sleeps through the quarter that terrifies the second. Acquaintance with the evils was the edge.
This is not a counsel of caution — Sun Tzu does not say the acquainted general avoids war; he says he alone can run it profitably. Risk literacy that ends in "therefore do nothing" has missed the verse’s point entirely. The instruction is to study failure modes as the prerequisite of aggression, not as an alternative to it.