“If the enemy is taking his ease, he can be harassed; if well supplied, starved out; if quietly encamped, forced to move.”
Do not let the rival rest, eat, or sit still; constant pressure erodes a stronger foe.
Chapter 6 gets specific about how the weaker side moves the stronger: at ease, he can be harassed; well supplied, starved out; quietly encamped, forced to move. The verse is a catalogue of comforts — and Sun Tzu’s insight is that comfort is not a luxury but the maintenance system of strength. Deny the maintenance and the strength degrades on its own schedule.
A dominant incumbent’s comfort is its renewal cycle: customers auto-renew, reviews are perfunctory, pricing floats upward. A challenger doesn’t attack the product — it attacks the comfort, publishing an honest switching-cost calculator every renewal season and timing its discount window to the incumbent’s renewal quarter. Within two years the incumbent is re-pricing defensively and running its first "value" campaigns in a decade: forced to move, starved of the easy margin.
Harassment here is structural, not personal — denying comfort means removing the conditions a strong rival relies on, not pestering individuals or badmouthing. And it must stay inside the ethics of your market; the moment pressure becomes nuisance, it recruits sympathy for the incumbent. The blade goes into the supply line, never the person.