Anyway, it's an over-reaction. It's boiling away the oceans to keep the enemy navy from reaching your shores, and destroying the atmosphere to keep the enemy bombers from flying over your cities. Why do it?
Because if the enemy does reach your shores, it will kill half your people and enslave the rest. And you have little chance of avoiding this outcome by other means.
And it's boiling away a part of the ocean/atmosphere you rarely use.