While it was initially intended that NCAC would operate as an integral part of the British 11th Army Group, Stilwell refused to work under General George Giffard and was made subordinate to the Supreme Commander of SEAC, Lord Louis Mountbatten.

In 1942, Northern Combat Area Command was formed at Ramgarh Cantonment, in India, from X Force: units (including the 22nd and 38th Divisions), which had retreated out of Burma.

For the campaigning season of early 1944, NCAC was augmented with Merrill's Marauders – a brigade-sized formation created by the US Army for commando -type operations in Burma.

During 1944, NCAC forced the Japanese 18th Division to retreat out of northern Burma and US Army engineering battalions, assisted by Indian laborers built the Ledo Road – which joined the northern end of the Burma Road and reestablished communications between India and China.

In 1945, under Sultan's command, NCAC – which now included the Chinese New 6th Army – aided in the drive to retake the rest of Burma.

Many times during World War II, British and American commanders in India were frustrated by their Chinese allies.

To watch Stilwell, when hard pressed, shift his opposition from one of the several strong-points he held by virtue of his numerous Allied, American and Chinese offices, to another was a lesson in mobile offensive-defence.At a meeting to sort out the operational chain of command for the three fronts in Burma, Stilwell astonished everyone by saying "I am prepared to come under General Slim's operational control until I get to Kamaing".

During the offensive, NCAC intelligence staff serving under General Stilwell repeatedly underestimated Japanese troop strength in Burma.

The American equivalent of the Chindits, Merrill's Marauders also suffered from the same treatment during the campaign, consistently being asked to perform missions that were beyond their power without superhuman effort.

However, the Japanese 33rd Army under General Masaki Honda performed a very creditable delaying action against the forces attacking them.

In the end, it was events on the main front further south that forced them to withdraw, as they were in danger of being cut off from their supply lines.

36th Division was used to support the left wing of the Fourteenth Army under Lieutenant General William Slim.

In October 1944, due to personal disagreements with Chiang, Stilwell was recalled to the United States by President Roosevelt.

His former role was split as was the CBI Theater: His replacements were not only less abrasive characters but as they each concentrated on one area there was less institutional conflict and confusion.