In a post-apocalyptic future, when a reckless government agent learns that his long lost brother is a test subject in a brutal military experiment, he helps a terrorist cell fight through a dangerous wasteland to free a host of captured children.

Thank everyone for the help! I appreciate it.

I completely agree that this sounds very intriguing. My only caution is starting with the words "post-apocalyptic." Versions of the world are pitched so often that everyone hears it and thinks "not another one," even while they're smiling at you. Might be worth your while to come up with another kick-ass way to describe "post-apocalyptic." I also agree with other posts about the length -- shorten it a bit.

>>I wouldn't thing the current American public would be all that happy if their current government had spent a generation or two using children as lab rats either,

Is there any credible proof that they have? If you place the story in the future, you don't have to worry about making it a credible reality, here and now; you have greater freedom to define the situation any way you want to.