World War II basically got rid of the shackles of traditional warfare and already had the prototype of modern warfare. To a certain extent, the war in that period was a contest of comprehensive national strength, especially industrial strength.
On the eve of World War II, Japan was at best a second- or even third-rate industrial country. In front of it are the United States, the Soviet Union, Germany, the United Kingdom and other countries.
Let's first look at the indicator of industrial output value.
In 1938, the United States and Japan accounted for 28.7% and 3.8% of the world's total industrial output, respectively, and the gap between the two was huge. Despite the great crisis of 1929-1933 and the decline of the capitalist economy, the United States maintained its position as the world's largest.
The economic historian Rostow, in his book The World Economy: History and Prospects, calculates:
From 1936 to 1938, capitalist industrial countries accounted for 76% of the world's total industrial production, of which the United States alone accounted for 32%.
Overall, the economic power gap between Japan and the United States is huge. Only when the economy is stronger can you have money to invest and mobilize more resources to go to war.
Statistics show that during the Pacific War, the U.S. military invested more than 90% of the total financial expenditure, that is, $281.5 billion in military expenditure to support the war. Even so, everything is working properly in the United States.
This is due to the strong position of the US dollar in the international monetary system. As soon as the American war machine is launched, it can use various means to induce the capitalist countries to share the costs with it.
Japan is much more embarrassed than the United States. In the middle and late stages of the Pacific War, Japan's military industry and military expenditure accounted for 85% of GDP. Driven by high military expenditures, Japan's national economy is on the verge of bankruptcy. If it were not for the support of the complete militarization of the national economy, I am afraid it would have fallen apart.
In 1937, the Japanese government's fiscal revenue and expenditure was 4.7 billion yen, and the same war of aggression against China consumed 3.3 billion yen. Converted into US dollars, Compared with the United States, Japan is really a small witch. It can also be seen from this that Japan's military expenditure is at the expense of exhausting national strength and financial resources.
In addition, Japan's economy and military dependence on foreign countries are severe. Historical records record:
Japan, the former copper-producing country, was only half self-sufficient during the Showa period. Copper was the largest demand in 1940, at 234,000 tons, while the continent's highest production in 1943 was only 123,000 tons. Half of the copper is imported from the United States, Canada and Central and South America. The United States produces 50 percent of the world's copper.
Copper is an important metal for making weapons, such as bullets. To a certain extent, Japan's weapons will be in the hands of other countries. In particular, copper is in the hands of its opponent, the United States, and Japan's arms supply is naturally unsustainable.
Such a Japan is not an adversary of the United States at all. Japan also had an objective understanding of its own strength, and finally made a desperate bet to bomb Pearl Harbor.
This is actually a crazy move. After Pearl Harbor, the United States was fully involved in the war machine, greatly increasing military spending, and the U.S. army became more and more powerful in the war, and even became the strongest army at that time.
In terms of backup support, Japan also does not have an advantage. Japan's territory is narrow and slender, with almost no strategic depth. Moreover, heavy industry, which is related to the lifeblood of the economy, is concentrated in the three major metropolitan areas of "Tomeisaka". In the event of war, these cities could easily be the preferred targets for air raids. The subsequent bombing of Tokyo and the atomic bombing of Nagasaki in Hiroshima amply illustrate this point.
In contrast to Japan, the United States does not have these problems. If the Japanese army is lucky enough to land on the American mainland, the strategic depth of the vast east-west area will be the biggest obstacle restricting the Japanese army.
Overall, even in the absence of any external interference, the United States and Japan fought to the death, and its outcome can be predicted.