>>92
>>90
Or you could just use ultimatums and alliances. If you have the ability to launch and win a 'pre-emptive' war, they probably weren't a threat to you in the first place. Which is why every pre-emptive war in history has been a badly disguised war of aggressive conquest and enslavement. A pre-emptive war cannot be justified no matter how you stretch your hypothetical. It will always be an unprovoked war of aggression.