Generals:Sneak Attack

From Command and Conquer Wiki

Later in the conflict, high-ranking GLA generals were able to order the engineers of the underground Tunnel Network to instantly tunnel up through the ground and create an entrance anywhere currently visible on their radar, without the need for a Worker on the surface to construct it. This way, they could launch shocking surprise attacks even from within the enemy's own base. The exit did take some time to be ready and could be collapsed if under heavy fire, especially from siege weaponry. This tactic was developed by Prince Kassad, but when Kassad went rogue the technology was taken from him and distributed throughout the GLA by an anonymous general. Leaders of the GLA restricted use of this tactic to certain generals who had received "promotions" as it required exposing the managers of their underground networks.