User blog comment:Chaoswolf75/What's the hardest choice you've had to made throughout the series?/@comment-1683278-20120711165639/@comment-3325589-20120712103012

Not everybody can save both. It requires the player to make a lot of decisions correctly, and it's possible to screw yourself over before you even get to ME3 (especially if Tali died or got exiled). Of course, you can go back and get things right in a new ME2 file, or use a save editor if you're playing on PC, but still, there are some ME2 saves that can't broker peace.