Excerpt - FORWARD OPERATING BASE KALSU, Iraq, Aug 16 (Reuters) - U.S. forces launched an airborne assault on a desert compound south of Baghdad on Thursday, the first air strike in a major new offensive. A company of airborne infantry struck villas in search of Sunni Arab militants. The assault was a first part of operation Marne Husky, itself part of a countrywide push announced this week against both Sunni Arab and Shi'ite militants. Major-General Rick Lynch, commander of U.S. forces south of Baghdad, told Reuters on Wednesday that about 4,000 of his men would be involved in the operation...