- This article is about an in-universe event. For the in-game mission, see Annex.
After Valais Air Base was successfully defended, the Allied Forces began preparing a counter-attack while Belka was still in limbo. The first objective was to retake Arlon, a rural plain located in north Sapin. Arlon specifically held Route 171 in it, connected by three bridges over the Aare River. With these bridges in Belkan control, Belka had the perfect opportunity to send a line of troops right through and invade even further into Sapin territory. This threat needed to be removed; with Route 171 under Allied control, supplies could move much more smoothly between Osea and Sapin.
The Allied Forces sent in the mercenary units once more, again comprising of the Galm Team of Pixy and Cipher. The two immediately began to engage the tanks and anti-air units stationed at the three bridges; there weren't too many, as Belka had gained quite a lot of land in a short amount of time, and their forces were spread thin. They had some light air support in the area, but they weren't of much help.
There were also some houses and windmills along the route. Without chancing the possibility that these would contain more Belkan supplies, Cipher had chosen to destroy them and hope for the best.
Route 171 fell in a short amount of time, attributed to the lack of suitable forces in the area to deal with the Galm Team. A supply route was linked in Arlon between the Allied Forces on both sides, and Ustio was prepared to assist in a full-blown counter-attack.