a strong position that an army has captured in enemy land, from which it can go forward or attack the enemy 桥头堡（部队在敌占区内夺取的据点） - [usually singular]
a good position from which to make progress （进一步前进的）立足点，据点 This agreement will be a bridgehead for further talks. 该协议将成为进一步谈判的桥头堡。