Coalilition, hell no, the SCF began their intervention as soon as it reached day 4, the orbital bombardment of key areas on the enemy's land began, focusing on bases and fortifications... the Troops has begun to land, focusing on utilizing the SCF's technological superiority to blitz into the enemy areas, they also have began to deploy troops to help american ones, the Mechs the SCF uses are monarchs, formerly UPEK mechs that was reverse engineered to now work for the SCF, the beginning of SCF troops to line up across the american-Dominioneer border has begun, knowing the combine uses stuff like THIS as a time to attack, the SCF has also begann to help america with space superiority incase the dominioneers invade... the Combine is weak, the Federation is strong! FOR GLORY AND PROGRESS!
(note the SCF is the PU-NE version of the UISC)