Air Operations, Bismarcks

• As Allied bombers and fighters step up their pre-invasion attacks against Japanese troops in the Cape Gloucester area, 70 V Bomber Command B-24s, B-25s, and B-26s attack the Cape Gloucester airfield on New Britain, 37 B-24s attack the Cape Hoskins airfield on New Britain, and more than 20 B-25s attack targets in the Borgen Bay area.
• 475th Fighter Group P-38s down 3 fighters near Cape Raoult at 1145 hours.
• Efforts by AirSols aircraft to attack Rabaul are thwarted by bad weather.

Air Operations, CBI

• 27 308th Heavy Bomb Group B-24s, escorted by 28 14th Air Force P-40s, attack the airfield at Namsang while several 14th Air Force P-40s strafe the Laihka airfield.

• When Japanese bombers attack the airfield at Kunming, 16th and 26th Fighter squadron P-40s down 2 Ki-21 'Sally' bombers and 4 Ki-43 'Oscar' fighters over the base between 1110 and 1125 hours.
• 5 11th Medium Bomb Squadron B-25s attack Nanhsien while 2 B-25s attack a freighter in the Hainan Strait.

Air Operations, Europe

• Weather severely limits the bulk of flight operation by the 12th and 15th Air Force units, but XII Air Support Command A-36s and P-40s are able to attack a variety of tactical and communications targets in central Italy.

• 15th Air Force B-26s attack the Antheor viaduct and several road and rail bridges along the Var River.

Air Operations, Marshalls

14 VII Bomber Command B-24s attack the Mille Atoll.

Air Operations, New Guinea

• 33 3rd Light Bomb Group A-20s attack bivouacs and dumps near Finschhafen.
• A P-39 with the 71st Tactical Reconnaissance Group’s 82d Tactical Reconnaisance Squadron downs a D3A 'Val' dive bomber over the Huon Peninsula.

Air Operations, Solomons

• 19 XIII Bomber Command B-24s attack ground targets around Chabai and Porton, 10 B-24s attack supply dumps at Kahili and 5 B-24s attack a supply dump at Bonis.
• 11 42nd Medium Bomb Group B-25s attack Korovo, 5 B-25s attack Japanese Army ground troops at Poroporo (Choiseul) at low level, and AirSols fighters attack numerous targets of opportunity on Bougainville and Buka. Also, XIII Bomber Command B-24s mount individual attacks against Kahili, Kieta, and Poporang while conducting armed-reconnaissance flights.

Bougainville

The 1st Battalion and 3rd Battalion of the 21st Marines conduct a double envelopment of Hellzapoppin Ridge behing close support of TBF Avengers and TBD Dauntless dive-bombers. The marines lose 12 men killed and 23 wounded in capturing this important piece of key terrain.

CBI

Generalissimo Chiang Kai-shek gives Gen Joseph Stilwell command of Chinese forces in India and those in the Hukawng Valley in Burma. This is a largely symbolic act, for Chinese commanders still secretly take orders from the Generalissimo. Thus, commanders often ignore or respond very slowly to Stilwell's orders.

China

Chiang Kai-shek gives Gen Stilwell command of all Chinese troops in India and the Hukawng valley in northern Burma. Japanese aircraft bomb Kunming, in Yunnan. This action fits into the plan for campaign of strategic bombing aimed at disrupting the Allies' vital centers as a preliminary to an offensive against India.

Italy

5th Army takes Monte Lungo, making the German position at San Pietro less secure. There are violent German counterattacks all along 5th Army's front.

Early on, troops from US 36th Div enter San Pietro. To the north VI Corps is advancing all along its front as the Germans pull back a little way.

Mediterranean

The French submarine Protée is lost of Toulon, France with all on board.

New Britain

The American air force steps up its operations against targets in New Britain in preparation for the landing at Cape Gloucester.

Pacific

The US submarine Grayback (SS-208) sinks the Japanese merchant cargo ship Gyokurei Maru (5588t) east-southeast of Naha, Okinawa.

Images from December 18, 1943

Alexander Fleming, Scottish Bacteriologist

Manufacturing Penicillin

Douglas C-47's Enroute to Finschhafen

US Soldiers Loading Ammunition

Destroyers on Anti-Submarine Patrol