Hussein considered the Palestinian issue to be the overriding national security issue, even after Jordan lost the West Bank in 1967 and after it renounced claims to it in 1988. Initially, Hussein attempted to unite both banks of the Jordan River as one people, but with the formation of the PLO in the 1960s, it became difficult to maintain such a policy. He was relentless in pursuit of peace, viewing that the only way to solve the conflict was by peaceful means, excluding his decision to join the war in 1967. The decision cost him half his kingdom and his grandfather's legacy. After the war he emerged as an advocate for Palestinian statehood. After renouncing ties to the West Bank in 1988, he remained committed to solving the conflict. His 58 secret meetings held with Israeli representatives since 1963 culminated in the signing of the Israel–Jordan peace treaty in 1994, which he considered to be his "crowning achievement."