The Arab lands were distributed among the various sovereignties by the Paris Peace Settlement of 1919 - 1920. It established the British mandates of Iraq, Transjordania and Palestine, the French mandates of Syria and Lebanon; and the nominally independent kingdom of Hejas. A of wave of nationalism swept over all these Arab lands, during the post-war period.

Great Britain took charge of its mandates and adopted a conciliatory policy by handing over Mesopotamia (Iraq) to Prince Faisal, and Transjordania (Jordan) to Prince Abdullah, the sons of King Hussein of Hejaz, who became the Kings of Iraq and Jordan respectively.

Both the countries were claiming to represent the entire country. The war began with the invasion of troops from North Korea into the southern territory. This was the first time that the UN took direct interest in warfare. As the communist North was unwilling to withdraw troops, the UN sent their forces, consisting of militia sent in by about sixteen member nations, in support of South Korea. Ninety percent of the troops were sent by the United States. China and the Soviet Union lent support to the North. After much destruction of life and property, the war ended with an armistice in 1953. Both countries accepted the present line of battle as the line of demarcation. Since then many peace accords have been signed by the two countries in order to ease out mutual enmity.

Siam or Thailand, was under Japanese occupation in 1942. It declared war against the Allies. However, in 1946 it was declared by the country that this war had been imposed on it by Japan. Marshal Pibul Songgram ruled Thailand from 1947 to 1957, with dictatorial authority. In 1957, he was replaced by Marshal Sarit. Though Thailand was nominally a monarchy, it remained in the hands of a military faction.