The 1st Guards Infantry Regiment was quickly assembled and ready to move.
Because the Austrian border was monitored by a few Allied army posts, Mainz had to be cautious. Though small in number, these posts closely observed any movement toward Austria.
If Mainz commanded 200,000 troops, he could have driven straight in, ignored Allied surveillance, and solved the situation immediately. But he had only 2,000 men. Any alarm raised at this point could trigger a reaction from the Entente, giving them time to intervene and prepare—and that would ruin everything.
To achieve the German-Austrian merger, Mainz needed to act before the Entente noticed. Surprise was essential.
How to achieve such a surprise? Napoleon had already taught the world a lesson a hundred years earlier.
In 1800, during the Second Anti-French Coalition, Napoleon led four reserve troops across the Alps through the Great St. Bernard Pass to relieve General André Masséna, who was surrounded in Genoa. The unexpected arrival behind enemy lines led to decisive victories and helped break the coalition. Napoleon's bold move became legendary, and his words on the Great St. Bernard Pass—"A soldier who does not aspire to be a general is not a good soldier"—inspired countless civilians to join the army willingly.
Wanting to replicate Napoleon's daring maneuver, Mainz prepared to cross the Alps using the hidden mountain paths previously scouted.
The journey would be dangerous and time-consuming. If discovered, his troops would likely become trapped in the mountains. But if successful, they would avoid Allied eyes and enter Austria by surprise.
"Equip everyone in Austrian uniforms. Leave behind heavy weapons like artillery. Carry only light arms, mortars, ten days' rations, and necessary winter gear—clothes, gloves, hats," Mainz instructed.
Mainz was not ruthless, but he understood the extreme dangers of the Alps: snow-covered peaks, freezing temperatures, steep cliffs, and treacherous roads. Preparation was essential to minimize casualties.
"Guderian, take the 1st Battalion to lead the way. Mark the route as you go and ensure the paths are safe from snow hazards."
"Yes, Colonel! Mission will be completed!"
Guderian was thrilled. Though officially only acting as battalion commander, this assignment was both a promotion and a chance to prove himself.
Next, Mainz addressed another officer:
"Kesselring, you will manage logistics, including all wounded soldiers—whether they are transported into Austria or back to Rosenheim. The decisions are yours."
Unlike Guderian, Kesselring's assignment felt less glamorous. He had wanted to be at the forefront, not managing supplies. But Mainz's reputation and the life-saving favor he had granted Kesselring left no room for refusal.
"Understood, sir! Task will be completed!" Kesselring replied, grateful and determined.
Kesselring had recently been imprisoned in Bavaria due to a misunderstanding with local Freikorps and accusations of rebellion. Mainz had personally intervened to secure his release. Though Kesselring did not yet fully understand the political intricacies, he remained loyal and diligent, determined to honor the debt he owed Mainz.
"Good," Mainz said thoughtfully. "Your experience in logistics will ensure efficiency. The battlefield may rely on your work as much as on the combat troops."
For the generals leading troops into combat, Mainz had several other talented officers under his command:
"Schellner, your 2nd Battalion will follow the 1st Battalion. Alternate with them to secure the mountain passage."
Schellner's previous experience in the Alps made him ideal to support Guderian.
"The 3rd Battalion will follow under my command," Mainz continued. "Preserve your strength during the mountain advance. Once we exit the Alps, be ready for immediate combat."
The troops readied themselves, aware that the German-Austrian merger—and the future of their nation—depended on their success in this perilous operation.