In 1953, Major General Văn Tiến Dũng, then Commander of 320th Division, was recalled to Việt Bắc to assume the Chief of General Staff position. Thai was assigned as Deputy Chief of General Staff. In fact, he was appointed as Special Campaign Chief of Staff Điện Biên Phủ, assistant to the Commander in Chief Võ Nguyên Giáp. On 26 November 1953, he led a group of General Staff cadres to Tây Bắc.