Why is Egypt so wary of getting involved in Yemen’s conflict?

Egyptian forces arrived in Yemen in the thousands, backing the country’s government in a civil war against rebels that threatened to overthrow it. But this is not today’s war – this is 1962, and the Egyptians were supporting republican forces in North Yemen against the country’s royalists. The intervention came after Yemenis who were friendlier to the Arab nationalist ideology propagated by Egypt under President Gamal Abdel Nasser led a revolution that overthrew Zaidi Imam Mohammad al-Badr – a theocratic monarch. Although the republican side was ultimately successful in the war against the Saudi-backed royalists, Egyptian forces withdrew in the wake of their defeat in the 1967 war against Israel , and after also suffering heavy losses in Yemen.