There's a difference between someone who says something, and someone who acts out on it - and when they're in the business of selling weapons or profiting from it - and say something like that, which will lead to action or is inherently acted upon because of the nature of what they're doing (the business they are in) - then it's no longer just a "freedom of speech" thing.
You can say you want to kill someone, or even tell them you're going to kill them - but under law, it's only when you act on it OR have a plan to do so that the scenario becomes illegal - and you'll go to jail if you then kill said person (assuming you get caught) or have a plan to do so. Likewise, them just saying wouldn't be illegal, however I feel them acting out and selling actual weapons to both sides (and perhaps somehow inciting war between two parties to then profit) should IMHO be illegal, stating their intent they would and would love to is not only having a plan stated but perhaps one of the most disturbing disconnected inhumane uncaring violent acts a person could partake in.
I don't generally agree that killing of anyone is right - though perhaps with the only exception of those who actively kill others or lead violence - however that's for a society to determine what is acceptable. Unfortunately many things a society deems unacceptable (even existing laws that are enforced) are happening and go unchanged, though we're moving towards a system that is more in line with general views. There are more basic issues that need to be taken care of first to help alleviate people's worries and stresses, removing fear of survival will solve most, if not lead to solving all problems.
