Don't be afraid, that's just the Republicans talking.
The good news is that "the sky will fall if you do this" only works the first time. Obama ends torture, closes Gitmo, start obeying the law and...
American still stands. Which means he can keep doing what he's doing. He can do more. As long a America is still here, he's doing the right thing.
No matter what evil or stupid thing Bush did, the justification was always "At least we haven't been attacked" Well, we can turn that augment to support the good and the smart just as easily.