Scorched Earth Tactics

So, it occurs to me that it would very entertaining to give players the option of destroying their own system rather than allowing it to be captured by the enemy.

How? I imagine that it would take a certain amount of industry production to prepare a system for that purpose (it might also be a good idea to rig it so all industry production is cancelled for the system once the prep work is done for as long as you want to keep the option open), after which point a special "scorched earth" battle tactic is unlocked during ground battles which has the same effect as an obliterator missile strike.

Maybe it should be a tactic limited to one specific (and *very* petty) faction, maybe the effect should be scaled back so that only the planets that're already colonized are destroyed- I just know it would be very *very* funny to see a massive enemy fleet deploy thousands of troops to attack a system that you then immediately destroyed along with everyone in it out of pure spite.