NO... generally, pre-emptive strikes are ILLEGAL! (it all depends on what's "pre-emptive" to you. does it mean before any actual strike is thrown by the "agressor"? does it mean before the "agressor" does or says something that would make the reasonable person believe an attack is imminent?
Again, in the US, the agressor MUST say or do something that would make the reasonable person believe that an attack was imminent (going to occur immediately). Also, the act Must be no more damaging to the attacker that would be reasonable to defend him/herself.
Semantically, pre-emptive infers acting BEFORE the agressor makes such an action.
Also, generally, juries are dumb. The better attorney almost always wins (unless the evidence on one side is overwhealming"