CHINA (Fourteenth Air Force): In China, 2 B-25's hit warehouses and barracks on Nampang ; weather prevents completion of several other scheduled missions.
UNITED STATES: The USAAF activates HQ XX Bomber Command at Smoky Hill AAFld, Kansas. This new command will eventually have operational and administrative control of all B-29 Superfortress units in India.
BURMA: In the British Fourteenth Army's XV Corps area, the Indian 7th Division starts across the Mayu Range along two crude trails in preparation for an offensive.
SOUTH PACIFIC THEATER OF OPERATIONS (Thirteenth Air Force): On Bougainville 45 B-25's, Royal New Zealand Air Force (RNZAF) Ventura's and P-38's attack Bonis airfield; a few other B-25's strafe coastal villages in the Empress Augusta Bay region.
SOLOMON ISLANDS: Major General Ralph J. Mitchell, USMC, relieves Major General Nathan F. Twining, USA, as head of Solomons Air Command. Gen Twining later takes command of the USAAF Fifteenth Air Force in Italy.
On Bougainville, the 3d Marine Division is extending its positions in the vicinity of the Piva River forks against lively opposition. The 37th Infantry Division is unopposed.
SOUTHWEST PACIFIC THEATER OF OPERATIONS (Fifth Air Force): In New Guinea, 50 B-25's and B-26's pound Japanese positions in the Sattelberg area. A-20's hit the Lae area. 18 B-25s of the 345th BG escorted by four squadrons of P-47s attack the Hansa Bay area, no ships were spotted, but several barges sink or damaged and supply dump fires started. Well camoflaged AA batteries fired and damaged two B-25s, one force landed back at Port Moresby, the other B-25D 41-30522 ditched crew captured and killed. HQ 49th Fighter Group transfers from Dobodura to Gusap.
BISMARCK ARCHIPELAGO: A USN PBY-5 "Black Cat" Catalina of Patrol Squadron VP-101 sinks a cargo ship in Rabaul harbor during the night of 20/21 November. 50 B-24's bomb Gasmata.
GILBERT ISLANDS: U.S. Army and Marine Corps troops invade Makin and Tarawa Atolls. Air and naval gunfire bombardment precede and closely support assault teams. Aerial supremacy over the Japanese has already been achieved.
At both atolls, landing forces are beset with supply difficulties and communications failures.
Rear Admiral Richmond Kelly Turner's Task Force 52's landing force (the 27th Infantry Division's 165th Infantry Regiment reinforced by the 3d Battalion of the 105th Infantry Regiment, tanks of the 193d Tank Battalion, and other supporting units), under Major General Ralph C. Smith, invades Makin. (The 165 Infantry Regiment is the old 69th "Fighting Irish" Regiment of the New York National Guard.) As a preliminary to the main invasion of Butaritari Island, the largest of the Makin group, a special landing detachment sails for Kotabu Island at 0645 hours and secures the island without opposition. The invasion of Butaritari is begun on schedule at 0830 hours, when Boat Landing Teams (BLTs) 1 and 3 of the 165th Infantry start landing on Red Beaches 1 and 2 on the west coast. At 1041 hours, about 10 minutes behind schedule, BLT 2 begins landing on Yellow Beaches, located on the northern (lagoon) shore between On Chong's Wharf and King's Wharf. Both assault forces secure beach heads and with tank support push rapidly forward against light resistance, converging along the West Tank Barrier, where Japanese opposition
is overcome, although a small pocket remains to the northwest. Artillery is emplaced on Ukiangong Point.
Rear Admiral Harry W. Hill's USN Task Force 53's landing force (2d Marine Regiment of 2d Marine Division, reinforced by the 2d Battalion of 8th Marine Regiment and supporting units), under Major General Julian C. Smith, USMC, invades Betio Island, at the southwestern tip of the atoll, where an airfield and main Japanese forces are located.
Betio is 2 miles long and less than ½ mile wide The defenders are lead by Rear Admiral Shibasaki Keiji and 4,800 men with 50 artillery pieces and seven light tanks. The terrain ranges from sea level to 9 feet above sea level. Landings are made with great difficulty and very heavy casualties. Transports arrive south of the assigned area and at 0507 hours come under fire of previously alerted Japanese on Betio. While transports are moving northward out of range of Japanese guns, warships attempt, with some success, to neutralize Japanese positions. Aircraft deliver brief strikes before the forces land. Although H Hour is postponed from 0830 to 0900 hours, the first troops do not reach shore until 0910 hours. Marines land under direct fire, many wading from a partly exposed reef that fringes coast; upon reaching the shore, landing teams become intermingled and disorganized. Landings are made on three adjacent beaches (Red 1, 2, and 3, from west to east) on the northwest coast. The 3d Battalion, 2d Marine Regiment, the Red assault force, gains a beachhead on the northwest tip of the island but is isolated there. In the center, 2d Battalion, 2d Marine Regiment, is pinned down by Japanese fire on Red 2. The 2d Battalion, 8th Marine Regiment, favored by more protracted naval gunfire preparation, meets less opposition on Red 3 and gains a beachhead extending inland to the airfield. To strengthen their precarious hold on the island, the 1st Battalion, 2d Marine Regiment, from regimental reserve, and 3d Battalion, 8th Marine Regiment, from division reserve, are committed. Fortunately, Japanese counterattacks, expected after nightfall, fail to materialize, and meager gains are held. Shortly before the invasion of Betio, a scout-sniper platoon clears Japanese positions from the main pier, partly burning it in the process.
Off Tarawa the aircraft carriers of Task Force 50 cover both landings. Beginning at about 1755 hours, 16 Betty's attack Task Group 50.3 built around the aircraft carrier USS Bunker Hill and USS Essex and the small aircraft carrier USS Independence. F6F Hellcat pilots of Fighting Squadron VF-18 in USS Bunker Hill, shoot down five bombers and ship's gunners down four but one launches a torpedo that strikes the carrier's starboard quarter seriously damaging the ship; she retires for repairs.