Confederacy of Independent Systems Crisis

"With the Separatists on the rise, their desire for true independence will grow. Eventually, they will attack the Republic, seeking control of the galaxy. However, something is behind the Separatist movement, supporting it, perhaps even controlling it. All the Jedi can feel a massive shift in the force; we feel the power of the dark side growing. Whatever is behind the CIS, whether it is the Sith, or some new threat, these dark powers seek the fall of the Republic.... and that cannot be allowed to happen."

- Mace Windu

The Separatist Crisis (26 BBY–24 BBY) was the term given to the period of tension that immediately preceded the Clone Wars, which this crisis ushered in.