Bombardment can only achieve its objective when the amount of suffering inflicted upon non-combatants is sufficient to break down their resolution, and when the commander permits himself to be influenced or coerced by the sufferers. A threat of bombardment will sometimes induce the target to surrender, but instances of its fulfillment being followed by success are rare; in general, with a determined commander, bombardments fail in their objective. Further, intentionally intense fire at a large target, unlike the slow, steady and minutely accurate artillery attacks directed upon the fortifications, requires the expenditure of large quantities of ammunition and wears out the guns of the attack. Bombardments are, however, frequently resorted to in order to test the temper of the garrison and the civilian population, a notable instance being the Siege of Strasbourg in 1870.