以夷伐夷
yǐ​yí​fá​yí

use foreigners to fight foreigners

  1. 以 yǐ preposition
    by means of
    to use; by means of; with; using the tool or method introduced
  2. 夷 yí verb
    foreigners
    (bound form) derogatory term for outsiders or foreigners, often used in modern history before the 20th century
  3. 伐 fá
    to attack
    to send a military expedition against; to attack; to strike
  4. 夷 yí verb
    foreigners
    (bound form) derogatory term for outsiders or foreigners, often used in modern history before the 20th century