不首先使用

no first use (policy for nuclear weapons) / NFU

no; not so / (bound form) not; un-

head / chief / first (occasion, thing etc) / classifier for poems, songs etc

first (of all) / in the first place

early / prior / former / in advance / first

to make / to cause / to enable / to use / to employ / to send / to instruct sb to do sth / envoy / messenger

to use / to employ / to apply / to make use of

to use / to employ / to have to / to eat or drink / expense or outlay / usefulness / hence / therefore