Despite it's higher (than the B-52) operating cost, a dozen B-1Bs, operating from Oman, dropped half the bombs (by weight) delivered during the Iraq campaign. The B-1B usually carried 24 one ton JDAM bombs, and could loiter over the battlefield for up to eight hours. There are only 36 B-1Bs left in service. Another 32 are being retired, in addition to 32 that have already been taken out of service. Because of the exceptional performance of the B-1Bs over Iraq, it's now proposed that fewer B-1Bs be retired, and perhaps 45 be kept ready for combat. Originally, a hundred B-1Bs were built.