Gāi guó yǔ duō gè méngguó qiāndìng le fángwù tiáoyuē.
The country signed defense treaties with several allied nations.
Tips
usage
盟国 refers to countries formally allied through treaties. Compare with 同盟国 (allied nations — often specifically referring to the WWII Allies) and 友好国家 (friendly countries — a looser term for nations with good relations).