Operation CHIEFTAN. The beginning of the end.
Limping along through space, Harrington and Theisman made their plodding way back to SLDF lines by 14 May, 2770. It took another two months of hyperspace jumps and interminable briefings on the events of your reconnaissance raid to a half-dozen brigade, division, and corps commanders before you finally arrived back at Apollo and rejoined the other survivors of 17th Army in their bivouac in July of that year.
The SLDF had seemingly been idle while you were gone. Far be it from immediately leaping back into the fray to free their imperiled and imprisoned countrymen, General Kerensky instead took the long view, slowly building his forces and stripping SLDF depots across the anti-spinward half of the Lyran Commonweath. Under General DeChevalier, he dispatched multiple Regimental Combat Teams in what he called Operation INTRUDER to stage additional reconnaissance raids not to the borders, but actually into the occupied Terran Hegemony.
As the remainder of 2770 dragged on into 2771, the forces assigned to Operation INTRUDER began to return with their reports. The situation in the Hegemony was worse than Kerensky had feared. As best they could, they had made spoiling attacks upon Republican bases and formations, and delivered desperately needed supplies to civilian partisans when and where they could. Of note was the annihilation of the 19th Striker Regiment (part of the Third RCT, the "Eridani Light Horse") due to the actions of an Amaris agent within the Third RCT headquarters unit. While not the only unit destroyed, the brutal battle - less than two hours - and the high-profile of the action led the 19th's destruction to become a rally call for the SLDF. Slogans of "Remember the 19th" and "Bloody May" soon became a common sight on the sides of tanks, mechs, areospace fighters, and, in the case of the Four Horsemen, a WarShip.
At the same time, the SLDF began to see something if had only rarely encountered in its entire history: defections. Soldiers were not running away from the SLDF - far from it - but defecting away from their active-duty military units in service to the Great Houses and making their way however they could across the Inner Sphere to join up with the SLDF. At first a trickle, these defections soon grew to a torrent, capped off by the sudden (and panic-inducing) appearance of two Draconis Combine WarShips at a pirate point over Toland. Whole companies and battalions of Mechs and vehicles, and whole squadrons of areospace fighters and DropShips arrived en masse. Some, especially those originating from the Draconis Combine, which had expelled the SLDF completely in 2770, had to fight their way through their own nation's troops to get there, so strong was their conviction. Eventually, Kerensky decided to stop using these troops as replacements for holes in SLDF orders of battle, and formed the Volunteer Corps. By 2772, the Corps consisted of twelve Volunteer Brigades (thirty-six regiments) from across the disparate nations of the Inner Sphere.
While very few SLDF formations had seen no combat experience whatsoever, few had seen as much as the remnants of the 741st. Throughout the fall of 2770, the five remaining companies of the 741st were broken up to serve as training cadres for SLDF forces. Echo Company was assigned to XXX Corps (Twelfth Army) until the spring of 2771, when you were instructed to move your cantonment to instruct the 2nd Volunteer Brigade, rotating between their three regiments as necessary.
By the end of 2771, preparations for the invasion of the occupied hegemony were nearing completion. In highly public snubs, Coordinator Minoru Kurita and Captain-General Kenyon Marik both informed the SLDF in no uncertain terms that they would not support the SLDF in their invasion in any way. Marik went even further, formally expelling the SLDF from his nation and denying Kerensky the chance to train forces there or to stage troops in Free Worlds League space.
The other three nations all gave Kerensky permission to utilize their realms as staging grounds, each providing a handful of worlds close to the Hegemony as forward operating bases. While no nation was willing to provide direct military assistance, the economic and military support assistance (for example, munitions production) they agreed to provide would prove invaluable.
As prepared as possible, the SLDF began to leave Rim Worlds planets in January of 2772. By the special request of General McEvedy, the 741st was reconstituted to two battalions of strength, and re-staged as a single unit again for the first time in almost two years. The 741st reverted away from their temporary assignment to V Corps, 11th Army and rejoined their parent formation, LXXII Corps, 17th Army. Both these Armies were assigned to 15th Army Group (General Dinara Pantazi, Commanding) and made a part of Task Force Commonwealth under Admiral Joan Brandt.
The invasion of the Terran Hegemony, otherwise known as Operation CHIEFTAN, was conceived as a three-pronged simultaneous assault targeting nearly every Hegemony border world, as well as all the worlds jointly controlled by the Hegemony and surrounding states. The overall strategy was simple: by targeting a broad front (with assaults being launched from Capellan, Davion, and Steiner space), he hoped to place significant pressure upon the Republican defenders and deny them the opportunity to shift forces around their system of interior lines in an effort to defeat each Task Force in detail.
Each Task Force was composed of three to four Army Groups, with General Kerensky himself leading Task Force Confederation, and General DeChavalier leading Task Force Sun. The largest of the three Task Forces was Admiral Brandt's Task Force Commonwealth; who also had by far the largest front, with target worlds ranging from Bordon along the FWL border to Nashira, a world shared with the Draconis Combine. 17th Army's first-wave targets included Cor Caroli, Galatea, Mizar, and Syrma, but acting in accordance with General Kerensky's directive, Admiral Soong (17th Army CO) planned to hold LXXII Corps in reserve during the first wave.
On 00:15 hours (local), 14 July, 2772, the first of 17th Army's WarShips dematerialized from the Alcor system's nadir jump point. Operation CHIEFTAN, the first steps toward Terra, had begun.