Foothold situation
From The Stargate Omnipedia
An emergency situation within the S.G.C., where an alien incursion has taken over the Cheyenne Mountain complex, and is using it as a beachhead for further conquest.
A simulation of this type of scenario is used to test potential new entrants into the Stargate Command operational staff.
KEY EPISODES
Foothold - Samantha Carter informs Maybourne that there is a Foothold situation at the S.G.C.
Proving Ground - A simulated foothold situation is used to test the leadership qualities of Elliot, a lieutenant fresh out of the military academy.