Declare a state within the next 12 months regardless of the state of the neogotiations. The Israelis cannot have the veto power especially that almost every country on the face of this planet will immediately acknowledge it and those who don't will eventually do including Israel. If the Palestinians wait for 24 months, the U.S. will be in the middle of a presidention election and will not be in the mood to acknowledge it.
Palestinian reportedly shot dead by Israeli soldiers after approaching Gaza border fence (Haaretz)
from the article: Carter: Palestinians seriously weighing one-state solution