After Six Day War, Arab states provided less support for PLO in their struggle against Israel, Egypt and Syria were more concerned in regaining their own lands than helping refugees
Now Gaza and West Bank were under Israelis, Palestinians realised they would have to fight for everything
350,000 more refugees from West Bank, mainly in Jordan, so Fatah concentrated recruitment there, 1967-70: Cross-border raids between Fatah in Jordan and Israel (and vice versa)