Nod forces are faster than we thought. The staging base you destroyed was a secondary base they were bringing on-line. We've located their main base, and need it removed in order to secure the area.
GDI has already established a foothold in the area, but needs an experienced commander to take charge and finish the Nod base off. That's where you come in.
Locate the Nod base and use whatever means necessary to destroy it.