Israel is basically a welfare state living off the tit of America. Why would we give them 10 billion a year to buy other people armaments?
Without America, there is no Israel only Palestine.
Firstly, most of that money is foreign aid, which they'd get anyways. The US also gives them money specifically so that they can buy and maintain US armaments, which is really just supporting the defense industry through a proxy.
Second, America would still be supporting them, just that Europe would be its primary arms suppliers. America would still be working with them in other ways.
Third and most importantly, Israel is not a welfare state. The country has a substantial trade deficit and does get support form the US, but it does not need them to survive - and in this case, they could finance the difference with London or Paris fairly easily. It would be able to finance itself via Brussels later on, too.
In short - Israel could survive without America.