Captain Archer was taken to the future; this very act caused major fluctuation in the time line and the future Federation was never founded.
Simple divices allowed Archer to send instructions back to Enterprise.
The resourceful crew, taken hostages by Sulliban, managed to trick them to activated a device, which brought Archer back.
In the mean time The crew faked an imminant warp core explosion and scared the Sulliban off.
Archer hijacked a sulliban cell ship and reunited with Enterprise.
Why not kill Silik, head of Sulliban?
Does anyone know about time travelling and the temporal war, beside Archer and T'Pol? Do Starfleet and the Vulcan high command know? If not, what would disclosure of the information cause?