The challenge is to create a modern-day Crusade - an attempt to use armed force to establish a Christian state in the Holy Land. No POD before 1949, so the target of said crusade will be the State of Israel.
Here's the most plausible scenario I can devise: the US and UK end up leaning towards the Arabs, resulting in an Israeli-Soviet alliance. This in turn gives new life to the "Jewish Bolshevik" canard, with the corollary that Christianity is associated with capitalism. A movement among American Christians to establish a "Free Christian Republic" in Israel emerges.
Any thoughts? Or would Israel simply become another member of the Soviet bloc (albeit one that remained a functioning democracy)?