If NK launches a nuclear attack, then immediate and effective retaliation is warranted.

However, to initiate a preemptive strike is fraught with incalculable risk.

Firstly, there will be broad condemnation across the world for such an action.

Secondly, the reactions of the other nuclear powers in the immediate and long-term is a great risk; placing the world at risk of nuclear war is too dangerous.

If we did have to take military action, we would likely use conventional forces to avoid the nuclear threshold.