If the US ever became anti-Jewish enough that Jews would fear for their safety, consider that without US support Israel would fold within a short time thereafter.
In other words, if the US ever became unsafe, then noplace is safe, which is why AIPAC spends so much attention on the state of the US political scene
Doubtful. Israel was doing very well before close ties with USA were established in 1967.
For example during Suez War of 1956 it was France and UK siding with Israel while USA was opposing it. BTW it was after 1956 when France decided to help Israel with nuclear technology.