When can YOU kill ?

When can you kill ? Ohhhh its a nasty question isn't it ? Sounds way over the top ?  Well our country can kill for furthering democracy abroad , thats o.k .... yeah ....  and we can aid the deportation of Julian Assange of wikileaks to eventually face  a death sentence in the USA , that's o.k too . And you can terminate a unborn but thats a grey area still too for some but i'll place it with the above as questionable but probable .