From a Cold War perspective, it makes sense. The Soviet Union & China where on more friendly terms with the Arabs, whereas the U.S had backed Israel. Syria, Iraq, Libya & Egypt also had actual Socialist governments.

There's a similar case for White & Black Nationalism. The Apartheid, Portuguese and Rhodesians governments were at war with the Black militias who directly allied themselves with the Communists. When these countries where toppled or replaced with Black Nationalists they had left-leaning parties (i.e ANC in South Africa, Mugabe in Zimbabwe, MPLA in Angola).