Soundwave was observant, it was a helpful trait but it was also enough for him to know that Starscream hated this war, a civil war fueled by greed and petty differences. The seeker had once been a bot of science, rational. But he had left what he knew and what he knew and protected to be a pawn for a leader he hated in a battle not own, leaving him freedom behind.
Soundwave belied that Starscreams mind slipped away from rationality and sanity more every day. His spark beginning to embrace the battle, every day he believed more and more and was even now beginning to think of him self as a better leader, as if it was his own cause. The aloof communications officer felt like he could help, like he could remove a bit of his abrasiveness and maybe return his spark along with his sanity, he wanted the one thing that he could hold onto. In fact he respected the seeker for his bravery even if it was the product and torn circuits.
Soundwave admired him because he thought that he himself would never be able to do something like rebelling, let alone succeeding. He was the model pawn in Magatrons game, the perfect drone of war, even if it as only out of fear but he hated himself for it, for following the strong and reducing himself to what he thought was nothing.
Although he felt a feeble hope every time Starscream triumphed as if he could save him from what was no longer a rut but a gorge, He felt a slight pride not only in Starscream but im himself for believing in something rather than following.