The Fertile Crescent Plan was an Iraqi Hashemite proposal for the union of the Kingdom of Iraq with Mandatory Syria (including Mandatory Lebanon), Mandatory Palestine, and Transjordan. Nuri as-Said, prime minister of Iraq, presented the plan to British officials during World War II, when it appeared that France had become too weak to hold on to Syria.

The second People's Party, representing northern Syrian commercial and landholding interests, favored the Fertile Crescent Plan and initiated diplomatic steps to implement it. However, the National Party and factions in the army were determined to block any plans for unity with Iraq as long as it had a military treaty with Great Britain. It was also opposed by Syrians who did not wish to live under a monarchy or in a pro-British state. The closest the plan came to fruition was during the regime (August-December 1949) of Colonel Sami al-Hinnawi, who had installed a People's Party government that entered negotiations to achieve unity. The opportunity was aborted by Colonel Adib Shishakli's coup d'état. Any faint hope remaining for the Fertile Crescent Plan ended with the overthrow of the Iraqi monarchy in July 1958.

Aspirations to unite the Fertile Crescent states continue to exist.^[1][2]

• Arab Federation
• Fertile Crescent
• Greater Syria
• Syrian Social Nationalist Party
• Damascus Protocol
• Sykes–Picot Agreement
• Pan-Arabism