Little objection was received from the Republic, as most officials saw it as a waste of resources. The main reason being there at all was that the Republic wished to keep the extensive baradium mines out of Imperial hands. On top of that, the Alliance Commander and Supreme Commander Jace Malcom previously agreed on a deal that Republic defectors to the Alliance were not considered traitors and that the Republic wouldn't attempt to retrieve them.
While seemingly a peaceful transfer of ownership, Republic General Amos Rike prepared an invasion force that swiftly took the mines hostage. While the Alliance was free of KIA's, they refused to let the traitors hold its territory.
The Alliance had only confirmed that the Republic did not officially support Rike's actions, and were told the Alliance was free to deal with the situation as needed.
Eventually, the Commander coordinated a task force of recon specialist and other operatives to eliminate the threat. The Commander aimed to inflict minimum casualties and damage to resources to the loyalist, as the Alliance could salvage their equipment, and recruit whoever wasn't as willing as others to wage war on the Alliance.
The Alliance was only able to maintain a beachhead, as Republic artillery was constantly bombarding the area, creating a "No Mans Land" between the Alliance and Rike's main forces.
From here, the Commander led their team through a series of bunkers, disabling artillery and anti-air, freeing Alliance air support to aid the team and other scattered forces. Republic forces were relentless, several loyalist leaders sacrificing themselves in attempts to hold off the Commander, ultimately failing. In the final moments of the battle, the beachhead was secure, wounded evacuated, and support forces on site. All that remained was Rike, who had commandeered a prototype hover tank from an unknown Republic source. After his tanks destruction, he attempted to eliminate the whole team in a suicide bombing. However, he was cut down before the detonation could set off.
The Alliance wished to learn how such a large force and respected general could sneak past the Republic and its senate in attacking another superpower. It was later revealed that several anti-Alliance elements were present in the Republic. These elements were confirmed to be in the military.
As a result, Alliance leaders prepared for a worst case scenario: War with the Galactic Republic. And no doubt the forces embedded in the Republic did the same.