Pacific theater

Collins was chief of staff of the Hawaiian Department from 1941 to 1942 and served as the Commanding General of the 25th Infantry Division—nicknamed the "Tropic Lightning" Division—on Oahu and in operations against the Japanese on Guadalcanal between 1942 and 1943 and on New Georgia from July to October 1943. At the time of his appointment in May 1942 he was the youngest division commander in the United States Army, aged 46. To serve as his assistant division commander, Collins specifically selected Brigadier General John R. Hodge, a decision he never came to regret as Hodge, who later became a full general, proved himself to be up to Collins's high standards.^[14]

It was during the campaign in Guadalcanal that Collins gained his nickname of "Lightning Joe", for his dash and aggression.^[13][12] It was also during this campaign that saw Collins awarded with the Silver Star, the citation for which reads:

The President of the United States of America, authorized by Act of Congress July 9, 1918, takes pleasure in presenting the Silver Star to Major General Joseph Lawton Collins (ASN: 0-2274/0-5247), United States Army, for gallantry in action against the enemy while serving as Commanding General, 25th Infantry Division, in action on 11 January 1943 at Guadalcanal, Solomon Islands. To visit the command post of an infantry battalion of the Division commanded by him, General Collins walked through some 800 yards of recently captured ground infested with enemy snipers. Upon arriving on Hill 52, to gain better points of observation, he voluntarily exposed himself to intermittent rifle, machine gun and mortar fire, without regard for his own personal safety. From there, he located an enemy machine gun nest and personally assisted in placing mortar fire on it and on other areas likely to be occupied by the enemy, while bursts of enemy machine gun fire hit many times but three yards away. His calmness and fearlessness under fire was an inspiration to the officers and men of the infantry regiment in that sector. His example and words of praise and encouragement with which he continually encouraged the men in the forward units spurred them on and contributed materially to the success of the offensive operation. His gallant actions and dedicated devotion to duty, without regard for his own life, were in keeping with the highest traditions of military service and reflect great credit upon himself, his unit, and the United States Army.^[15]

Lieutenant General J. Lawton Collins receiving the Companion of the Order of the Bath from British General Sir Bernard Montgomery at Munchen Gladbach, 1944.

Major General J. Lawton Collins (right) explains to Lieutenant General Omar Bradley (left) how Cherbourg was taken, July 1944.

Western theater

Collins was later transferred to the European Theater of Operations (ETO), where he commanded the VII Corps in the Allied invasion of Normandy and on the Western Front through to the end of World War II in Europe in May 1945. Collins was chosen by Lieutenant General Omar Bradley, who had served with Collins at the Army Infantry School before the war and was then commanding the First Army in England, as a replacement for Major General Roscoe B. Woodruff, the original commander of VII Corps and one of Bradley's West Point classmates. Woodruff was senior to Collins but had no experience in amphibious operations. Collins was appointed after a brief interview with Bradley and General Dwight D. Eisenhower, the Supreme Allied Commander, about his combat experience after Collins summed up his tactical approach in the Pacific as always targeting the high ground in an attack. Bradley turned to Eisenhower, claiming that Collins "talks our language."^[16] At the age of 47, this made Collins the youngest corps commander in the United States Army. Among the units serving under Collins' command in Normandy was the veteran 82nd Airborne Division, commanded by Major General Matthew Ridgway, a fellow graduate of the West Point class of 1917.

General Joseph Lawton Collins challenged the 1106 Engineers Combat Group to build the Rhine River pontoon bridge at Bonn, Germany in 10 hours and he would have a beer party. There was a beer party for 600 soldiers.

VII Corps played a major role in the Normandy landings in June 1944 and the subsequent Battle of Normandy, including Operation Cobra. Collins was a favorite of the 21st Army Group commander, General Sir Bernard Montgomery, who after Operation Goodwood laid the path for VII Corps to break out in Operation Cobra on 27 July 1944.^[17] After Cobra was the Battle of the Falaise Pocket, which completed the destruction of the Wehrmacht in Normandy, the corps then took part in the liberation of Paris and the Allied advance from Paris to the Rhine. In early September VII Corps took approximately 25,000 prisoners during the Battle of the Mons Pocket.^[18] It later broke through the Siegfried Line and endured heavy fighting in the Battle of Hürtgen Forest.^[19] VII Corps later played a major role in the Battle of the Bulge, the largest battle on the Western Front during World War II, and finally took part in the Western Allied invasion of Germany. VII Corps is perhaps best known for the leading role it played in Operation Cobra; less well known is Collins' contribution to that plan.^[13]

Major General J. L. Collins, commanding VII Corps, with Field Marshal Sir Bernard Montgomery, commander of the 21st Army Group, and Major General Matthew Ridgway, Commanding XVIII Airborne Corps, December 1944.

One of the few senior United States commanders to fight in both Europe and the Pacific, against the Germans and Japanese respectively, Collins contrasted the nature of the enemy in the two theaters of war:

The German was far more skilled than the Japanese. Most of the Japanese that we fought were not skilled men. Not skilled leaders. The German had a professional army... The Japanese.. didn't know how to handle combined arms – the artillery and the support of the infantry – to the same extent we did. They were gallant soldiers, though... They fought very, very hard, but they were not nearly as skillful as the Germans. But the German didn't have the tenacity of the Japanese.^[20]

Collins was promoted to temporary three-star rank of lieutenant general in April 1945 and permanent brigadier general in June. He was very highly regarded by General Omar Bradley, Collins' superior for most of the war, and many German senior commanders believed Collins, along with Lieutenant General Troy H. Middleton, commanding the VIII Corps, to be one of the best American corps commanders on the Western Front.^[13] Bradley commented that "Had we created another ETO Army, despite his youth and lack of seniority, Collins certainly would have been named the commander." For his service during the war Collins was three times awarded the Army Distinguished Service Medal, twice awarded the Silver Star and twice the Legion of Merit.^[21]