Mica Goldstone
Agents/Opertives cannot use special actions to perform 'Big Movie' events.

An agent cannot remove the fails for the power systems within a starbase, thereby causing a critical overload leading to the annihilation of the entire starbase and half the planet. Nor can they turn all the power off in a starbase effectively closing down every complex and turning all the security/weapons systems off-line.
At best a special action may allow the operative to rig a one use bomb at an outpost with a huge stoclpile of hydrocarbons.

Keep in mind what an agent/operative is, he is a facet of the game with power within the scope of the game equivalent to his value. Even Bond at his very finest only destroyed a small island (outpost equiv to 5 complexes - Research, factory, training, command, security).