Sorry it's 3 am & I'm tired but can't sleep, let me clarify:
Add this to the building you have the button on:
Code:
Behavior = OCLSpecialPower ModuleTag_XX
SpecialPowerTemplate = SuperweaponTacticalNuclearStrike
OCL = SUPERWEAPON_ SuperweaponTacticalNuclearStrike
CreateLocation = USE_OWNER_OBJECT
ScriptedSpecialPowerOnly = Yes
End