He was the chief ideologue and creator of cultural campaigns during the pre-World War II military rule of Field Marshal Plaek Pibulsonggram.

During his five years in Europe, Wichitwathakan served as a member of the Siamese delegation that attended and participated in deliberations of the League of Nations in Geneva.

While Wichitwathakan continued to work at the Ministry of Foreign Affairs, Madame Lucienne collaborated with him in several of his important historical publications, notably Prawatsart Sakon (Universal History).

[5] Luang Wichitwathakan subsequently married Prapapan Raphiphan, a teacher of history and daughter of Khun Vorasarndarunkit who was in charge of education in northern Siam under King Rama V. When Pridi Phanomyong started the clandestine party called Khana Ratsadon (People's Party), he consulted with Thai friends in Paris, namely Field Marshal Pibulsongkram, Wichitwathakan, Prayoon Pamornmontri, and Thatsanai Mitraphakdi.

He led an irredentist campaign after being presented a map produced by Ecole Francaise d'Extreme Orient showing the Thai race inhabiting the areas of Siam, Burma, and southern China.

Wichitwathakan estimated from this map that there were approximately 60 million Thais inhabiting the lands of southern China and Southeast Asia, and through his personal crusade as both a historian and a politician, as well as chairman of the parliamentary committee in charge of making the name change, succeeded in changing the name of the country from Siam to Thailand when the state convention ratified the committee's proposal in 1939.

His wife, Khunying Wichitwathakan, requested and obtained a personal audience with General Douglas MacArthur during which she succeeded in explaining to him that as foreign minister, her husband had no alternative but to negotiate a treaty of free passage in exchange for maintaining the independence of Thailand.

Among the principal allied forces, the British and the French wanted Pibulsongkram and Wichitwathakan to face the firing squad while the US alone insisted on a trial.

[citation needed] In 1958, Luang Wichitwathakan participated in the coup d'état staged by Field Marshal Sarit Thanarat that removed Pibulsongkram from power.

He served Field Marshal Sarit as his closest confidant and advisor and played an active role in promoting Thai nationalism.