Why did Gamal Abdel Nasser send Egyptian troops to Yemen in 1962?

In 1962, elements of the military in North Yemen staged a coup that overthrew the monarchy and established the Yemen Arab Republic. The new republican government, led by 'Abd Allāh al-Sallāl, requested assistance from Egypt to defend the fledgling regime against royalist forces, who were attempting to regain power with the support of Saudi Arabia.1

In response to this request, Gamal Abdel Nasser sent Egyptian troops and equipment to support the Republican Army in the ensuing civil war. This intervention was part of Nasser's broader regional influence and his support for revolutionary movements in the Arab world. The Egyptian military presence in Yemen continued until 1967, when troops were withdrawn following the outbreak of the Six-Day War between Egypt and Israel.213