Sentence:  In his submission to the UN, [Christof] Heyns points to the experience of drones. Unmanned aerial vehicles were intended initially only for surveillance, and their use for <WSD>offensive</WSD> purposes was prohibited, yet once strategists realised their perceived advantages as a means of carrying out targeted killings, all objections were swept out of the way. 
Meaning of the word marked with <WSD> tags:  Relating to an offense or attack, as opposed to defensive.