(n)bridgehead, footholdan area in hostile territory that has been captured and is held awaiting further troops and supplies“an attempt to secure a bridgehead behind enemy lines”, “the only foothold left for British troops in Europe was Gibraltar”
(n)beachhead, footholdan initial accomplishment that opens the way for further developments“the town became a beachhead in the campaign to ban smoking outdoors”, “they are presently attempting to gain a foothold in the Russian market”