A quick, limited mission assumption underestimated the actual battlefield

Bowden shows how the raid's planners expected the operation to capture key lieutenants of Aidid's faction and be complete within roughly an hour, based on previous similar raids in the city that had gone smoothly. This expectation shaped everything from the equipment soldiers carried to the backup plans in place, leaving units under-supplied for a fight that would stretch through the night.

The assumption proved catastrophically wrong once the mission encountered far heavier and more coordinated resistance than intelligence had anticipated, revealing how previous successes can create a dangerous overconfidence about what an adversary is capable of mounting in response. Aidid's militia and armed civilians turned out to be far more organized and numerous than the raid's planning had accounted for.

Bowden uses this gap between plan and reality as a recurring lens throughout the book: military plans are built on the best available intelligence, but urban combat's chaos can overwhelm even careful planning within minutes.

Takeaway: plans built on past success can create dangerous overconfidence about how an adversary will respond next time.