cordon sanitaire
noun [ C ] uk/ˌkɔː.dɒ̃ sæn.ɪˈteər/ us/kɔːrˌdɑ̃ː sɑː.niˈter/ cordons sanitaires uk/ˌkɔː.dɒ̃.sæn.ɪˈteər/ us/kɔːrˌdɑ̃ː.sɑː.niˈter/
封锁线；防卫圈
a guarded area around a place or country that prevents people from entering or leaving it
NATO was accused of trying to throw a cordon sanitaire around Russia. 有指责称北约试图封锁俄罗斯。