Under this constant threat, Israel was safeguarded by the world's largest power, the United States, and because of this Israel has been able to keep itself safe from any attack from neighbouring governments.

What a false sentence, where was the US during the war in 1948? Why was the US providing intelligence for the Arabs in the 1967 war( that's what the USS Liberty was doing)? Why did they rescue Yasser Arafat and the PLO when they lost the war in Lebanon?

When has the US protected Israel from attack? Name one time the US has militarily protected Israel.

This may help to understand why the peace process has never moved forward.

A better reason is that the Palestinians have rejected every offer of peace and said(many times) that they will accept nothing less than Israel's destruction.

Even knowing all this, how is it possible that the state of Israel is not being penalized?

Penalized for what ? Defending themselves from their enemies? The Arabs who ethnically cleansed them from the entire middle east. You speak about the Israel lobby yet fail to mention the Arab lobby that spends 13 dollars for every dollar spent by Jews on lobbying.