bargaining chip
noun [ C ] uk/ˈbɑː.ɡɪ.nɪŋ ˌtʃɪp/ us/ˈbɑːr.ɡɪ.nɪŋ ˌtʃɪp/ (UK also bargaining counter)
（为达成协议的）筹码
something that someone else wants that you are willing to lose in order to reach an agreement
Missiles were used as a bargaining chip in negotiations for economic aid. 谈判中导弹被用作了换取经济援助的筹码。