A visa-system is for people visiting a country as far as i know. If you stay too long inside a country that is not your own, you can be expelled. Nowhere will you lose your right to come back after you've been out of the country for too long. I hold the passport of the country of my parents origin and I could immediately move there if I wanted, even though I've never lived there in my life. I guess you must be living in the US, where people usually don't travel abroad.
UN agency warns school may be delayed for Palestinian refugees due to lack of funding (AP)