Should humanity ban guns and weapons? Should the United States go first?
Do you think that if we banned guns an alien civilisation would make peaceful contact with us when they had observed that we were no longer violent savages?
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Banning anything necessitates the need for superior force to enforce said ban. If your question is "would aliens talk to us if everyone voluntarily decided not to ever use violence as a coercive strategy?" you're asking the wrong species. Why do you put it on an extraterrestrial civilization to bring you enlightenment?