Never before had so many served in uniform. In 1934, fewer than ten million persons worldwide were in the military. In 1944, the total neared one hundred million. Larger still was the amount of yen, pounds, rubles, marks, crowns, and francs spent to make it all happen. By 1945, several belligerents were allocating 60 percent of their national budgets on the war. In 2005 dollars, the conflict’s overall price tag was in the low trillions.

Most citizens in the services were not volunteers. Many never envisioned themselves ever being in the military. Not until the late 1930s, when an ARMS RACE accelerated rapidly, did conscription become endemic. Whatever the commitment level, troops universally expressed a desire to get the fighting over with as soon as possible.

Enlisted soldiers ranged in age from ten to sixty, officers from eighteen to eighty-eight. In a war of unbridled nationalism, most armed forces were not homogenous. Sixteen percent of Lithuania was not Lithuanian. A quarter of Romania and nearly a third of Poland were of varying backgrounds. The largest ethnic group in the United States was (and still is) German.1

From this mix of the global family came the biggest assortment and assembly of combatants in history. Listed below, in order of total number of persons mobilized, are the largest national forces in the war.2

1. SOVIET UNION (21,000,000)

ENTERED WAR:       1939

PEAK STRENGTH:    13,200,000

The largest country on the planet, the Soviet Union also had the largest armed forces ever assembled under one flag. By 1945, there were as many veterans in the Soviet Union as there were people in Mexico. More Soviet women served in the Red Army than Frenchmen served under Charles de Gaulle.

Often referred to as “the Russians,” the Soviets were a multiethnic assembly. In 1940, only half were Great Russians. The rest were Ukrainians, Byelorussians, Lithuanians, Poles, Georgians, Jews, Armenians, plus a hundred other ethnicities. Out of a total population of 190 million, 11 percent served in the military. Of these, the vast majority were in the massive Red Army. Fifteen of sixteen Soviets in uniform were ground troops.


Victory came at an exorbitant price for the Soviets, yet they were fortunate to avoid a two-front war with Japan.

At the start of the war, the Soviet armed forces had an extremely poor reputation internationally. Perceived as undisciplined, unwieldy, and unmotivated, the Red Army confirmed this image with a disastrous performance against greatly outnumbered Finns in the WINTER WAR of 1939–40. Yet as following events would prove, the Soviets may have been poorly trained and at times ineptly led, but they tended to fight tenaciously when placed on the defensive.

Of the roughly twenty-one million Soviet troops that were mobilized, half became casualties.

2. GERMANY (17,900,000)

ENTERED WAR:       1939

PEAK STRENGTH:    9,500,000

Restricted by the VERSAILLES TREATY to one hundred thousand ground troops and no navy or air force, Germany began all-out remilitarization in the mid-1930s. By 1939, it had the second-largest army and best air force worldwide. The Kriegsmarine, though far behind, had an adequate submarine arm and was hoping to eventually add aircraft carriers to its fleet.

Nearly a fourth of the population served in the war, the highest percentage of any country. For every German in the Waffen SS, there were two in the navy, four in the Luftwaffe, and twenty in the army. The majority of troops served on the eastern front. Infantry, artillery, and tank crews were five times more likely to be deployed to the East than anywhere else.

Neither the German public nor its armed forces were eager to wage war, especially since the previous contest had rather unfavorable results. But victory in Poland after a mere three weeks brought a great sense of relief if not patriotism. Seven months later, offensives into Western Europe seemed to go even better, capturing six countries in six weeks. Quick Balkan victories the following year only solidified a sense of greatness. Many assumed that the invasion of the Soviet Union would also end quickly and favorably.

Though the reputation of the German soldier remained high throughout the war, success of the German armed forces began to wither after the massive assault of Barbarossa. Numerically, the German army would not peak until late 1944, but their performance had reached a high point in1941.


Germany had some of the best ground troops in the war but could not replace the numbers they lost.

The Waffen SS was supposed to be Nazi Germany’s elite guard of pure Aryans. By 1945, more than half the Waffen SS were not German. One-third were Romanian. The rest were Croatian, Dutch, Hungarian, Italian, and Ukrainian, plus a few Muslims.

3. UNITED STATES (16,354,000)

ENTERED WAR:       1941

PEAK STRENGTH:    12,000,000

In 1936, Americans spent 1 percent of the national budget on defense and ranked about seventeenth in the world in military power. Less than a decade later they had the second-largest army on earth, by far the largest navy, and the largest air force. The marines by themselves nearly equaled the entire armed forces of Australia.

For every twenty Americans in uniform, ten were in the army, five served in the army air force, four were sailors (of which two served on land), and one was a marine. Overall, Americans were the best paid and best fed service personnel in the world.

Of sixteen million in uniform, only five million served overseas, illustrating how the United States was empowered by logistics and supply. Each American soldier in the field was supported by four tons of equipment. In comparison, material support for each Japanese soldier averaged out to a few pounds. Distance also mandated a high proportion of U.S. troops committed to supply. The United States stood three thousand to seven thousand miles away from most battle zones.3


Reflective of their mountainous support network, only one in three U.S. servicemen served overseas.

Of Americans enlisted in the war, less than half possessed a high school degree.

4. CHINA (14,000,000)

ENTERED WAR:       1937

PEAK STRENGTH:    5,700,000

Although China was the most populous nation on earth with nearly five hundred million inhabitants, it had the smallest percentage of combatants among the major powers. Less than 4 percent of all Chinese served in an army during the war. Never a single “armed forces,” China’s defense was more of a patchwork of regional militia, CHIANG KAI-SHEK holding the largest collection. His Nationalist forces initially held most of the country, but by 1938, Chiang and company were desperately holding on to the rural center around the city of Chungking (Chonqing).

In northeast China, the Communists were generally effective in winning over the population and debilitating the Japanese. As the empire concentrated troops in cities and along rail lines, the Communists operated around the pockets in between, blending into the local population and employing guerrilla tactics along vulnerable points. Only once did the Communists mount a large, organized offensive, the so-called Hundred Regiments Campaign in 1940. Killing more than twenty thousand Japanese, it also convinced Chiang that his rivals were becoming too powerful. From that point onward, the war was not China versus Japan but the Nationalists versus the Communists versus Japan.4


Poorly armed and generally poorly led, the Chinese fought and died in large numbers.

Due to a lack of communication equipment, Chinese officers often had to be at the head of their columns in combat. As a result, the officer class died at a rate five times faster than the enlisted.

5. JAPAN (9,100,000)

ENTERED WAR:       1937

PEAK STRENGTH:    7,500,000

Though it often appeared as if the Japanese navy was the largest branch of the imperial armed forces, the army outnumbered its naval counterpart, on average, three to one. The heaviest commitment had always been China, where Japanese manpower ranged from 800,000 to 1,500,000. The Allies rationalized backing the inept CHIANG KAI-SHEK on the belief that his Nationalists were “tying down” the bulk of the Imperial Army.

It was the army that achieved most of Japan’s great successes, conquering Hong Kong, Burma, the Dutch East Indies, Singapore, Malaya (Malaysia), and the Philippines. Of course, these would have been difficult if not impossible without the temporary dominance of the Imperial Navy.

Japanese armadas had a temporary advantage over their opponents. Although the Imperial Navy was the third largest in the world in 1941, it could concentrate its forces, whereas Britain and the United States had to disperse their warships across the globe. This competitive edge allowed Japan to score a string of phenomenal victories in late 1941 and early 1942, highlighted by the attacks on PEARL HARBOR and the sinking of Britain’s treasured battleship HMS Prince of Wales off of Singapore, both achieved days within each other. Yet success was fleeting, so to speak.

The Imperial Navy had the two largest battleships ever made, the Yamato and Musashi. Each was nearly as long as three football fields and had 30 percent more displacement than the largest U.S. battleships ever built.

6. ITALY (9,000,000)

ENTERED WAR:       1940

PEAK STRENGTH:    3,100,000

Although huge in number, the Italian armed forces were poorly outfitted and unmotivated. Far from cowardly in combat, the Italians were simply not prepared for the job. Tanks were of archaic design with flimsy armor and limited firepower. Artillery was at a tenth of the volume of World War I and outdated. The navy had no radar, no sonar, and no aircraft. The air force, what little there was, consisted of a fair number of biplanes.

Essentially, the military was a metaphor of the country—fragile and fragmented. Mussolini came to power by way of the militia, a.k.a. “the black shirts,” not by the support of the military. In twenty years, Fascist Party influence never took root among the armed forces. In fact, Italian soldiers and sailors were bound by oath to the king, not to Mussolini.

Facing defeat after defeat, the armed forces suffered long after the fall of il Duce. In 1943, the Wehrmacht invaded the country from the north, capturing and disarming more than three hundred thousand Italian soldiers, sending most of them to Germany as slave labor.5

One of Italy’s defeats actually created an Axis victory. In November 1940, the RAF launched a surprise torpedo attack on Italy’s naval base in Taranto, sinking three battleships. Impressed by the results, the Japanese naval high command reasoned the same could be done against a fleet at Pearl Harbor.

7. GREAT BRITAIN (5,896,000)

ENTERED WAR:       1939

PEAK STRENGTH:    4,683,000

The British Isles were predominantly a sea power at the outbreak of hostilities, with a navy ranked second in the world, but its navy was the smallest of the three military branches. From an overall population of 47 million, nearly 4 million served in the army, 1.2 million were in the RAF, and 900,000 were in the Royal Navy.

Arguably, Britain’s army bore the brunt of the war. In 1939 it numbered 400,000, smaller than the army of Belgium. Climbing to 1.6 million by 1940, Britain’s ground forces still went on to amass an extremely poor record, although not for lack of trying. Driven from France and Norway in 1940, then Greece and Crete in 1941, the British nearly imploded when they lost Singapore in early 1942. A following string of losses in Burma and North Africa did not help matters.

With the British armed forces stretched too thin across the empire, lacking reliable tanks and antitank guns, not until Second El Alamein did the royal luck turn for the better, mostly because of vastly superior numbers in vehicles and men. Combined operations with the United States from 1943 onward led to better fortunes in Sicily, Italy, and France.

Like the Soviet Union, Great Britain drafted women into service. By the end of the war, 10 percent of the British armed forces was female.

8. FRANCE (3,500,000)

ENTERED WAR:       1939

PEAK STRENGTH:    2,680,000

France was a paradox. At its strongest, it lost. At its weakest, it prospered. In 1940, at its apex in men and equipment, with the fourth largest army and navy in the world, France suffered its worst defeat in the war, beaten in six short weeks on its home turf. Nearly half of France’s armed forces went through the war in captivity. The Third Reich captured 1.5 million Frenchmen and French colonials. Those who did not die or escape remained POWs or were slave laborers in Germany for the duration.

At the end of the war, ranking eleventh globally in military strength, playing a tertiary role in the liberation of its own country, France possessed zones of occupation in Germany and Austria.6

A substantial cause of both scenarios was France’s global positioning. It started the war with three armies—one guarding France proper, one covering North Africa, and one guarding colonies elsewhere—a system heavily dependent on the work and sacrifices of colonial subjects.

In 1940, the setup compromised France’s military might on the Continent. In the interim, it was France’s savior. The Free French movement started its comeback when French Equatorial Africa decided to back Charles de Gaulle over Vichy France. Other colonies began to switch over, and the momentum changed for good with the Allied invasion of French Morocco and Algeria. By 1945, thanks to shrewd bargaining, the French were again a global power, albeit a military prune.

In 1940, the French army was ten times larger than the British army. In 1945, the British Army was ten times larger than the French.

9. INDIA (2,581,800)

ENTERED WAR:       1939

PEAK STRENGTH:    2,200,000

When Britain declared war on Germany, the British viceroy for the colony of India stepped in and proclaimed India at war as well. This did not go over well with the three hundred million Indians who were not consulted. British demands for obedience in the hour of imperial need led to a general breakdown of order. Most of India’s prominent civil leaders were arrested, including pacifist Mohandas Gandhi.

When the war started poorly for Britain, London officials moved to secure greater cooperation from the subcontinent, eventually promising to grant India its independence once victory against the Axis had been achieved.

This promise of autonomy spawned an explosion. The Indian armed forces grew from 160,000 in 1939 to more than two million by 1944. All of them were volunteers. Predominantly led by white officers, the poorly equipped but highly motivated army sent divisions to Europe, North Africa, East Africa, the Middle East, and Southeast Asia. Most were stationed as home guard, protecting the geographically vital subcontinent from invasion and providing air bases for Allied air transport to China over “the Hump” of the Himalayas. India’s crowning achievement occurred in 1944 and 1945 when it successfully fended off a Japanese invasion from Burma and then secured the country for the Allies. Of the “British” forces in Burma, seven out of ten were Indian.7

One of the problems with organizing the Indian armed forces was communication. At the time of the war, India (which included Pakistan and Bangladesh) was home to more than eight hundred languages and dialects.

10. POLAND (2,400,000)

ENTERED WAR:       1939

PEAK STRENGTH:    1,200,000

As with France, Poland had one of the largest armies on earth when Germany invaded. Unlike France, Poland had no colonies to fall back on and no victory parades waiting in its future. Yet many Poles went on to achieve great successes in support of the Allied effort.

Of more than one million troops routed in the blitzkrieg of 1939, some ninety thousand managed to escape by way of Slovakia and Romania. Many trained in France and were part of the ill-fated defeat in 1940, while portions of the small navy, including two submarines, were able to make it to Britain and assist in convoys and coastal defense. The first bright moment came in the BATTLE OF BRITAIN, in which the courage and marksmanship of Polish pilots accounted for one out of every eight German planes brought down.

While an untold number of regular army personnel formed the core of the resistance movement in and around Warsaw, exiled Poles served in North Africa, the eastern front, and Western Europe. Part of the NORMANDY invasion and the less successful OPERATION MARKET-GARDEN, Poles had their finest hour in Italy, capturing the abbey heights in the fight for Cassino, losing thousands of men in the process, but succeeding where three other assaults by other nationalities had failed.

While stationed in Palestine, several thousand Polish soldiers of Jewish descent deserted their units to live in the area. One of them became a rather proficient militant activist by the name of Menachem Begin.

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