 Complete the following phrase:  Once in Britain the division was attached to U.S. XVIII Airborne Corps, under Major General Matthew Ridgway, which commanded all American airborne formations, and which in turn became part of the First Allied Airborne Army when it was formed on 21 August, under the command of Lieutet General Lewis H. Brereton. Although attached to XVIII Airborne Corps, the division was not chosen to participate in Operation Market Garden, a large-scale airborne operation intended to seize several bridges through the Netherlands to allow the Allied armies to bypass the Rhine river and enter Germany. The 17th was passed over in favour of the 82nd and 101st Airborne Divisions because it had only recently arrived in the European Theater and was considered to be unprepared logistically as it was still collecting its combat equipment. The division, now with Colonel Edson Raffs 507th Parachute Infantry Regiment under commanda veteran unit which had 