What Steele is probably feeling right now is how the GTVA was feeling when they sent Steele to Sol in the first place : they are running out of time (for a ton of reasons), and they have to finish this, now. The Tevs are scared of the sekret project, they are scared of a civil war exploding at home, they are scared that their war in Sol is leaving them defenseless against a Shivan incursion. They are scared about what MORPHEUS implies.
In all that, the few victories caused by the Fedayeen aren't a major cause of concern by themselves, since the Tev still have a major military advantage, both in term of numbers and strategically. What is a matter of concern is that it made them loose precious time, and that's not something they feel they can afford.
Steele is not waging a war against the UEF. He's not even waging a war against the Fedayeen or Al'Dawa. Those are just pieces in his chessboard. The way I see it, what he's fighting, is time.