The phrase "powerful weapon" refers to an instrument or tool that has great strength, ability and effectiveness in achieving a particular goal. It can be used metaphorically to describe something that is very influential, potent or capable of causing significant impact or change. In the context of military operations, it could refer to a high-tech weapon system such as a missile, bomb or gun that has the ability to inflict massive damage on enemy targets. Similarly, in other fields like politics, business or personal relationships, something described as "powerful" can have immense influence and sway over others, helping achieve desired outcomes with great impact.