A "Unilateral Declaration of Independence" will be an utterly meaningless act, as the Palestinians do not control their own destiny, and they never have.
It is unfortunate that they CHOSE to follow the lead of their Arabic brethern, and attempt, over and over again, to destroy Israel. In 1948, tThousands of them moved out of what was to become the "Jewish State", so that they would not be in the way of the Muslim Armies rolling the Jews right into the sea. Others, either because of poverty, or stubbornness, refused to move, but chose to openly support the Arabs in their attempt to eliminate the State of Israel.
But, the Arabs lost, big time. Those Palestinians that had openly supported the Muslim cause were expelled from Israel (as they should have been), those that had not were allowed to remain in Israel and have full Israeli citizenship (and that consisted of many thousands of people).
The Jordanians controlled the vast majority of what was supposed to become the country of Palestine, Egypt controlled the Gaza Strip and Syria a tiny sliver of the far northeast of that proposed state. Those Palestinians that had either voluntarily left Israel before the war, or who were expelled afterwards, were placed in squalid refugee camps, and never allowed to have ANY citizenship, in ANY country.
Even though they lived in, were born in, married in worked in territory either controlled by or that was actually inside Lebanon, Syria, Jordan or Egypt, they were not allowed to have citizenship in any of those countries. Instead, they were taught to hate Israel, to blame Israel for all of their problems, etc.
Between 1948 and 1967, the majority of the Palestinian lands were under Muslim control. BUT, they would not allow any country called Palestine to be formed. It was not until after the 1967 war, when Israel was invaded for the 4th time, conquered the entire West Bank, the Golan Height's and the Gaza Strip that Syria, Jordan and Egypt suddenly relinquished any claim to those territories that had been scheduled to become Palestine.
If the Muslim countries actually wanted Palestine to become a country, why didn't THEY form it between 1948-1967?
They had every opportunity, but instead, they annexed that land into their own countries.
They also prevented any Israeli from entering the West Bank, to visit any of the Jewish Holy Sites. They went so far as to refuse anyone entry to ANY Muslim country (with the exception of Turkey), if you had a Visa Stamp in your Passport from Israel. I know that to be fact, because the U.S. Army had to get me a new passport after I had been part of a Military Mission to Israel, and later went to Saudi Arabia.
Let's not have the bleating, tearing of clothing and general weeping and wailing for those poor Palestinians. In actual fact, they live much better under Israeli control than they ever have without it. The people in Gaza were much etter off economically under the Israeli's than they ave been under either the Palestinians, the Egyptians or now under Hamas.
The economy of the West Bank is a LOT better now than it ever was under the control of Jordan.
Yes, the people of Palestine deserve to have their own state. BUT, they also need to give up the idea of conquering Israel, and the idea that they are going to get Jeruseleum back. Had they NOT blocked the Israeli's from visiting their Holy Sites for the 19 years that the east side of that city was under Muslim control, the Israeli's MIGHT be open to such an idea. But they killed that idea by their own behavior.
The Israeli's have never stopped the Muslims from having access to THEIR Holy Sites. Frankly, I am somewhat amazed that they didn't bulldoze the Temple Mount when they conquered it, but they chose NOT to do that. Instead, unlike the Muslims, they chose to allow their enemies unfettered access to, and total control of, those buildings.
So long as Hamas, Hezbollah and the other radical Muslim organizations are powerful, and are calling for the destruction of Israel, there will not be a State of Palestine in any real sense. Israel would have to collectively decide to commit suicide to ever allow such a thing to happen.