Why would the Egyptian Gov't do such a thing?

Ana mish fahim, bgad. Why would Egypt put up a steel wall on the border to Palestine? Why would Egypt sign a treaty with ISRAEL? Wein el arab? Egypt is a poor but the least they could do is not put up a wall and let some palestinians in for a better life. What the heck. Why is Egypt doing this? Obviously, the media has affected the mind of prez. mubarak. I am not Egyptian, i'm lebanese/somali, but i'm just really curious.