I think peace would be a cooler answer though.
When at I rest I am dangerous - when peace and peaceful resolutions to problems is not at the forefront of agendas, there is potential for non peace or war or injustice.
When I leave, I am deadly - when peace is gone, and war is around, people die
When I move, nothing can stop me - peace movements have been very effective in affecting change (but this is a little weak)
Yet the smallest of babes overpowers me - they cry a lot and overpower the peace
But still, I'm happy to win whatever the answer is.
I want gold!