Because along with their equipment, their morale were broken by constant bombing. Have you ever experienced even a few minutes of 'carpet bombing'? I have when I was a youngster during the Vietnam War, and I was at the peripheral of the target area. It was not pleasant, to put it mildly. The ground can shake enough to knock a man off his feet. The air can contain enough junk from gas to dust to actual debris to choke the same man. At 'ground zero', a man can suffer permanent hearing loss and if the concussions from the shock blasts does not kill you, it will make you feel like you had gone a few seconds with Mike Tyson at his prime. Seconds, not minutes. Men have been known to lose control of their bodily functions just from artillery bombardment, not carpet bombing where a bomb is much bigger than an arty shell, and there may be just bruises or sprained joints on their bodies. Just like their bodies, their minds just barely survived by withdrawal and let their bladders and bowels -- go. If the bombing is 24/7, then there will be no sleep, even if you are underground. Your shelter will transmit enough noise and shocks to keep you literally awake for days. If the bomb is directly above, you will be tossed out of your bunk.
No one who has ever survived a direct assault from a single carpet bombing run is the same soldier after.
There will be short term rise in oil prices, but the reality is that for the long term view, the world will know that Iran will be defeated off the waters and the mines cleared. Prices will stabilize and decline.
