We are rapidly arriving at the point where decisions will be made as to whether an act of war has occurred. Not only this device, but others in the same class of mass casualty weapon, and could see the lids come off.
For example if aforesaid weapon was used to strike a large carrier with a crew of 4-5000, would, without doubt, bring about massive retaliation, so one had better be ready for incoming. I suspect that an invisible line is already drawn in the sand, and the powers that hold the keys know just how far they can go in terms of casualties. The risk of crossing said line is high.
IG