The primary duty of any state is the defence of its citizens. In extremis, this means not suffering military defeat. One of the decisive factors in any military conflict is geography. In World War II (and in the centuries before that) Poland was easily invaded and partitioned because of its lack of defensible borders, the US was able to build a massive military force from scratch because of the vast oceans separating the US from Germany and Japan, and Britain was not invaded in 1940 because of the existence of the English Channel and the inability of the German Navy to gain command of the sea from the Royal Navy (the same problem Napoleon had). The British air/sea base of Malta was instrumental in interdicting Axis supplies to North Africa, and, ultimately in helping ensure the defeat of Rommel. I could go on multiplying examples, but I think the idea is clear.
Pre-1967 Israel was a tiny and vulnerable enclave in a totally hostile environment. I remember seeing on television the Syrians shelling Northern Israel from the Golan Heights (before Israel's 1967 'aggression'!), which were a fantastic military asset. The Jordanians (no military lightweights, as their performance in 1948 had shown) were only a few miles from the sea. The Egyptians were on the southern border, and controlled the sea routes on either side of the Suez Canal. The phenomenal victory that Israel won in just six days left that country with rational and defensible borders for the first time in its modern history. The Sinai Peninsula was an excellent buffer zone against Egypt, the Jordan River protected the eastern flank and the Golan had been taken from Syria.
Any sensible state facing annihilation from sworn and irreconcilable enemies would have held those frontiers. It would also have expelled the hostile population from the 'West Bank' and Gaza, and especially from Jerusalem, avoiding the constant threat of unrest and terrorism. The opprobrium heaped on Israel from the Muslim and Arab states, the liberals in the West and the usual suspects of anti-Semitism would not have been any worse than it was. In any event, even after the failure of intelligence (and the pressure from the USA not to launch a pre-emptive war, which would again have saved Israel much grief, as it had done in 1967) led to the Yom Kippur attacks, and it was only by the courage of soldiers such as Zvika Greengold, the badly-hit IAF and the help of the Almighty that the Syrian tanks did not burst through into the plains of Israel. In Sinai it also took hard fighting and severe casualties to reverse the brilliantly-planned and well-executed Egyptian attack across the Canal.
So what do the Israeli governments do? Under constant US pressure, they return the Sinai to the military dictatorship of Anwar Sadat in return for a peace treaty and recognition (Ah, but what if the Muslim Brotherhood takes over from Mubarak or his successor?) They withdraw unilaterally from Gaza and destroy their own people's settlements in the 'occupied territories'. Any rational independent onlooker would ask 'Have these people a death wish?'
You will notice I have confined myself to practical defensive questions. It is not wise to put any trust in agreements with other governments. Leaving aside the possibility of bad faith, governments come and go. In my lifetime, King Farouk was replaced by Nasser and the Bath Party, King Faisal in Iraq was viciously assassinated and some rather nasty people took over, the pro-western Libyan monarchy was overthrown, the Shah was given a one-way ticket out of Iran, and the Hashemite Jordanian royal family has been very close to the precipice more than once. Assad in Syria probably sleeps with a pistol in each hand. In Turkey, we have seen the strains between Ataturk’s secular state and an Islamist revival.
I mentioned Kissinger pressuring Golda Meir not to attack first. We have seen US Presidents from Carter onwards demanding Israel concede land for 'peace'. The US has its own interests, and its dependence on Arab oil has seen it supporting the evil Wahabist regime in Saudi Arabia, even though that regime is fostering the growth of militant Islam all over the world. Yes, it is useful to have an ally who supplies a great deal of military hardware, but what happens if that ally changes its mind or is coerced into withdrawing support? Or if it suffers such economic catastrophe that it is no longer able to help?
Please forgive the length of this post. It sums up as: politics are transient, geography is permanent. Don't give up the Golan and don't bet the farm on the help of others.
'From the morning watch, even until night, let Israel hope in the Lord'