no one answered your question about why the US and Israel have had such close relations. A lot goes back to early US-Soviet relations. The Soviet Union maintained close ties with many of the Arab states in the Middle East, and the US- which had been rather neutral to the formation of the state of Israel- saw it as an opportunity to counter Soviet influence in the region. This precipitated a sort of back-and-forth over the years that followed, with increased belligerence and resentment by the USSR (especially in light of their immigration policies toward their Jewish citizens who wanted to leave).

Hope that helps. there are detailed records about the first back and forth killings between jewish settlers and the local arab/palestinian populations dating to the mid 1920s... the bloodshed began even before the state existed.