Is inventing "defensive" biological weapons right livelihood?

I read the following on the internet: > Working for DoD contractors could give a very fat paycheck. However, > there're ethical issues involved. If you decide to work for them, make > sure to make it clear you'll work for defensive capabilities, not > offensive ones. There're a lot of other areas DoD needs people to > build up their defensive programs, and these should be legit from an > ethical standpoint. Is inventing "defensive" biological weapons right livelihood?