"UNESCO's decision to admit 'Palestine' as a member state in 2011 in apparent breach of UNESCO's own Constitution has come back to bite UNESCO with a vengeance – as America and Israel now give formal notice of their intention to quit UNESCO on 31 December 2018.
State Department Spokesperson Heather Nauert asserted America's decision was not taken lightly and reflected U.S. concerns with mounting arrears at UNESCO, the need for fundamental reform in the organization, and continuing anti-Israel bias at UNESCO...
UNESCO anti-Israel decisions since 'Palestine' was admitted to UNESCO membership have included:
January 2014 – the cancellation of an exhibition at its Paris headquarters on the Jewish presence in the land of Israel.
October 2016 - disregarding any Jewish ties to the Temple Mount - only referring to it by its Muslim names – then several weeks later - passing a softer version of the resolution that referred to the Western Wall by its Jewish name - though still ignoring Judaism's ties to the site.
May 2017 – UNESCO's executive committee passing a resolution critical of Israeli conduct in Jerusalem and Gaza.
July 2017 - designating Hevron and the two adjoined shrines at its heart - the Jewish Tomb of the Patriarchs and the Muslim Ibrahimi Mosque - as a 'Palestinian World Heritage Site in Danger'.
UNESCO appears to have acted outside the terms of its own Constitution in admitting 'Palestine' to membership.
That decision was open to possible legal challenge for two reasons:
Only states can be admitted to UNESCO under Article II (2) of UNESCO's Constitution - and 'Palestine' was not a state..."