On 26 October 1942, Colonel Mundy received his prodigious Command Pilot rating. 

In November 1942, he was sent to Washington, D.C. as plans officer at AFRIT. 

From 30 June 1943 until 18 June 1944, Colonel Mundy served as Commander of Laughlin Field, Del Rio, Texas. 

At that time, he was transferred to the 33rd Fighter Wing, as its Commanding Officer, initially at Blackland, then in Waco Field, both in Texas. He served in this position until 25 August 1944.

On 26 August of that year, he was sent to Randolph Field, Texas to serve as Chief of Staff of its 2500th Base Unit. During this time he also attended the Army-Navy Staff College from which he graduated on 20 January 1945. 

He departed from Hamilton Field on 15 February 1945. Upon his arrival at Headquarters, XXI Bomber Command, he became Operations and Training Staff Officer with that Organization. Inasmuch as Mundy's prior 3rd attack Group had specialized in low level flying, he was called upon to help in the planning of the law level incendiary missions.

On 15 March 1945, Colonel George Mundy was named Commanding Officer of the 39th Bomb Group, 314th Bomb Wing, stationed at North Field, Guam, Colonel John G, Fowler, who had brought the Group overseas returned to his earlier position as Vice Commander of the 314th Bomb Wing. 

Colonel Mundy would serve as CO of the 39th Bomb Group until the end of hostilities precipitated by an unprecedented air campaign by the 20th Air Force - One that had destroyed 50 of Japan's largest cities as well as it's military capacity to continue the war. This was the first time in history that major nation had been defeated without a land invasion. 

On Guam, Mundy's first fourteen missions went well, but his fifteenth came close to being the last for him. On this strategic daylight raid against Nagoya, Mundy was flying as Command Pilot with Captain John Miranda's Crew 13 of the 60th Squadron. Struck twice by 120 mm shells, which tore off approximately eight feet of the "City of Galveston's" right wing, a couple of feet off its aileron, and doing severe damage to bomb bay doors and two engines. The crippled plane barely made it to a Point eight miles off the Japanese coast where the twelve men successfully bailed out and were picked up by submarine. General Mundy recalls that they were stripped by the souvenir hunting crew of the submarine who confiscated such prize trophies as flight jackets, helmets, sun glasses and 45's. George quipped afterward, "You don't come out with a thing except your life." He wasn't complaining though - it was a willing price to pay for 12-lives. 

Both Mundy and Miranda received Silver Stars for their superb leadership and competency during this life threatening experience. 

Colonel Mundy returned to duty on 3 July, about a week later, and went on to fly seven more combat missions - accelerating a total of 22 by war's end. 

An interesting incident involving Colonel Mundy and Captain Miranda occurred early on in their relationship, On this particular day the Colonel, seated at his desk in his Quonset hut, spotted John Miranda passing by. He called out to "Big John" to "stop in for a moment." 

He said, "John, I have two papers on my desk that deal with you. Please read them and tell me which one you think I should sign." 

One order cited Miranda for punishment under the 104th Article of War - misconduct with the M.P.'s. The other recommended him for promotion to lead crew commander. 

At the time, Colonel Mundy was intending to sign only one of them - not the two. Miranda read them over carefully, then smiled and said. "Colonel, I think you should sign them both." "I did," Mundy related, "and he got both,"