First strike and Preventive strike

First strike noun - The initial use of nuclear weapons to attack a country that also has nuclear weapons; considered feasible only when the attacker can destroy the other country's ability to retaliate.

Preventive strike and first strike are semantically related. in tactic in warfare topic. In some cases you can use "Preventive strike" instead a noun phrase "First strike".

Preventive strike noun - A strike that is carried out in order to deter expected aggression by hostile forces.

First strike and preventive strike are semantically related. Sometimes you can replace phrase "First strike" with "Preventive strike", this phrases are similar.