Japan would only have four fast carriers to attack with here I think. Shokaku and Zuikaku weren't done yet.
Maybe the IJN doesn't think of a solution for torpedoes in the shallow water of a port, so the attack is all dive bombers and horizontal (high level) bombers.
Also the IJN pilots are not honed to quite as sharp an edge. So the overall damage may be less.
Lexington, Saratoga, Yorktown and Enterprise are based in Hawaiian waters in Dec. 1940, Ranger and Wasp are at Norfolk. Hornet is just about to be launched.
Not even launched, either of them. The Japanese are also still flying the A5M Claude. There were only 65 A6M Zeros at the end of November 1940. Most of the naval dive bomber were also D1A2 biplanes.
I'm not of the caliber in terms of military-strategic expertise to disagree with any of you on the notion that a Japanese attack in 1940 would be harder, less successful, and less attractive. In fact, I'm going to agree completely that Japan going to war with the United States through a surprise Pearl Harbor attack in 1940 is a somewhat worse prospect for the Japanese than doing so in 1941.
If Japan was to make such an attack one year early, it would not be driven by confidence in the military capability and local tactical superiority, at least not quite so much. That being said, there are other ways to force the Japanese government of the day into making such a critical decision a year earlier, namely economic ones.
Before I sum up a brief stab at satisfying the OP, please tell me if my reasons why Japan
did not go to war with the ABDA+ powers in 1940 are inaccurate or incorrect.
1. The Soviet Union had bloodied Japan in skirmishes, and was a deadly serious threat to Japan's position in Manchuria while at peace with other great powers, namely Germany.
2. US-Japan trade and relations were in serious decline, but had not reached the critical point of complete breakdown, or no return.
3. Japan's economic situation at home was bad, but appeared surmountable if a stable detente could be reached with the US.
4. Japan retained either holdings of US dollars or the ability to trade for them--exporting stripped-out gold from everywhere if need be. Possession of US dollars or the ability to gain them was critical, given that the Yen (maintained more or less by Japan, Manchuria, puppet China, etc) was not freely convertible.
5. Japan maintained the means and ability to trade with the Dutch East Indies for materials critical to the war effort in China.
Hopefully with my priors cleared up, this summary-TL will make sense.
1930-2:
-The United States passes the Smoot-Hawley tariff, which among many other things imposes a duty on raw and processed silk imported from Japan, a major Japanese export earner.
-The Hoover administration attempts to put more pressure on Japan after the seizure of Manchuria by raising the duty in a largely symbolic measure.
-Silk prices shoot up in the United States (though a trickle of it comes from China). The boost in prices for ladies silk stockings in particular increases the potential gain from alternatives, especially as women still desired the look of smooth, flat legs.
-Japan is expelled from the League of Nations, and naval disarmament talks go into a deep freeze. The Depression and imminent election in the US limits attention and resources to naval expansion
-Chaing Kai-Shek prepares and launches a series of campaigns against the communists, who he believes to be a greater threat than the Japanese (as OTL)
-The UK, Empire and Commonwealth adopt Imperial Preference as a trade policy, which is designed to raise revenue and promote intra-Imperial trade at the expense of imports from most elsewhere.
1933-35:
-FDR's administration brings the US off the gold standard, and devalues the dollar. This makes US exports more competitive and Japanese exports more expensive to Americans.
-Failure of the Japanese and Americans to reconcile their trade disputes and naval disarmament concerns leads to retaliatory Japanese duties on American cotton, sparking an unusual trade war in the midst of US embrace of free(er) trade policies elsewhere. Disruption of the cotton trade infuriates the Dixiecrat wing of FDR's coalition.
-US agricultural subsidies through programs like the Agricultural Adjustment Administration expensively support cotton prices, among other crops to a large extent. (Greater than OTL for cotton.) This leaves less room in the budget, and still does not completely satisfy disgruntled southerners.
-The Japanese ultimately break with the London Naval Treaties and other disarmament agreements, and embark on a naval expansion program. The Japanese navy and army are fiercely defending their own budgets, to the long-term detriment of the rest of the Japanese economy.
-In Europe, the Nazi party comes to power, and Mussolini's Italy invades Ethiopia, snubbing noses at the League of Nations.
-The Soviet Union under Stalin embarks on a project of mass agricultural collectivization, which ends in disaster and brutality when the peasantry resists. This coincides with the massive expansion and development of the vast Soviet internal security apparatus. Stalin begins to ramp up security and propoganda to full-scale purges, after several half-baked plots are discovered against the Soviet State. Of course, some such plots do actually exist...
1936-38:
-Stalinist purges fall heavily on the Soviet military, which loses many of its brightest minds to show trials, such as Tukhachevsky and Zhukov. This rapidly has a very non-trivial effect on military effectiveness. Increasing severity of the purges leads to an increased incentive among Red Army leaders to consider an actual plot, if they can get past Stalin's paranoia, security, and the ironic collective action problem.
-Spain suffers a bloody coup that nearly falls into civil war, though severe unrest ripples through the country for the remainder of the decade. The new leader of the government, Sanjurjo, moves to blame, and ultimately expel or persecute communists in the country. They are blamed (not completely inaccurately) for the disorder following the coup, and offered as the reason the Spanish army had to remove the civilian government.
-Spain, and to a lesser extent Portugal, drift closer to Italy and Germany partly due to ideological affinity, but partly because of ideological hostility to the left-dominated French government. Spain not suffering a brutal civil war presents a facade of greater strength than OTL, with the new government downplaying or hiding continued disorder and unrest in the country.
-The Spanish coup and effective suppression/destruction of a western communist party as an organized institution sends shockwaves through the Soviet Union. Stalin is even more strongly convinced that the Red Army poses or potentially poses an existential threat to his power and control. Internal security and political officer penetration of the military intensifies along with the Great Terror.
-Italy completes its conquest of Ethiopia to the profound consternation of France and the UK. This sense of isolation draws Mussolini to Sanjurjo's Spain, Salazar's Portugal, and Hitler's Germany.
-Germany militarizes the Rhineland, annexes Austria and the Sudetenland by the end of 1938.
-What begins as a skirmish escalates to a significant border battle between Japanese Manchuko and the Soviet Union. Poorly led Soviet troops inflict heavier casualties on the relatively lightly armed Japanese, but co-ordination fails leaving the IJA the field and a victory. The Soviet commander is blamed, but implicates Japanese compromise of Soviet commands under questioning. This contradicts information available from other sources, but it is presented as truth in the show trial regardless.
-Japanese assessment of Soviet power declines, while the Red Army wildly overestimates the IJA's capability.
-Germany, Japan, Italy, and Spain sign the Anti-Comintern Pact. Japan uses the Pact to gain leverage in negotiations with the Soviet Union, which makes significant concessions in return for a loose non-aggression agreement.
-The IJA, particularly the rather independent Kwantung Army, takes the Pact and Soviet concessions as a green light to exploit an incident on the militarized border with China, and launches a full scale invasion in early 1937.
-In the United States, prolonged high silk prices have promoted the development of a new miracle of science: Nylon. Consumer products based on the material, like women's stockings, become available in 1938. Silk imports from Japan, long a source of hard currency for Tokyo, begin a precipitous decline even from post-tariff lows.
-Despite Japanese naval expansion and cold relations, US naval reamament is slow to develop. Amid mutually conflicting desires to balance the budget, maintain and expand New Deal programs, pay off WWI veterans bonus, etc, the US navy has to scrounge for what resources it can get for expansion.
-American pressure on Japan to end the war in China intensifies through financial and trade instruments less likely to be viewed as belligerent acts by domestic voters. Such pressure does however, begin to strain the Japanese economy.
1939-40:
-Germany absorbs Czechoslovakia, and begins to make demands on the Polish corridor and Danzig.
-Stalin, seeing fit to drive his enemies against each other, signs a non-aggression pact with Nazi Germany, while using the influence of communist parties to promote the cause of China.
-Italy annexes Albania
-The US continues to quietly tighten controls on Japanese trade.
-Japan is managing to supply and maintain its war effort thanks to additional trade with the rest of the world, but this trade is soon abruptly cut off.
-In the summer of 1939, Germany invades Poland after an ultimatum is rebuffed, marking the onset of WWII. France and the UK declare war on Germany shortly thereafter.
-Poland falls to blitzkrieg, and the Soviets move into their share of eastern Poland.
-Germany invades Denmark and Norway by sea and air, fiercely contested by the French and British. The Royal Navy faces expensive losses thanks to the Luftwaffe.
-The Low Countries are attacked and quickly overwhelmed by the German army, which in a series of rapid thrusts, cuts off the Maginot line from the rest of France, and nearly destroys the BEF, which escapes across the Channel in great disorder and severe casualties. Paris falls.
-Italy joins the war with a largely unsuccessful attack across the alpine border with France. Naval action in the Mediterranean attrits British strength, which focuses on maintaining Malta and Egypt.
-Spain, seeing the complete collapse of allied positions virtually everywhere, demands the retrocession of Gibraltar. The UK refuses, leading to desultory Spanish attacks across the Pyrenees. Gibraltar holds for the time being under the (generally insufficient) artillery brought to bear by the Spanish.
-France surrenders, and a puppet regime based in Lyon is set up. Much of the French colonial Empire declares for Lyon, but a Free French movement is supported by the British.
-Gibraltar falls after the heaviest air and artillery bombardment yet seen, preventing resupply. Malta as yet holds.
-Thailand, goaded by Japan, attacks Indochina shortly after the fall of France. The Thai army is not particularly strong, but neither are the French garrisons in the colony. Japan "mediates" a peace where Thailand receives territorial compensation, and Japan gains bases and other extensive privileges.
-In response to the Japanese-Thai occupation of Indochina, the United States restricts most exports to Japan to virtually nothing, and locks down sources of US dollars.
-The UK and Free Netherlands government, suffering heavy air attack in the British Isles and Mediterranean, join the US in the embargo, partly to appease US opinion, and partly to reserve supplies needed for the war.
-Stalin, seeing Germany and Japan locked in combat in France and China respectively, moves to enforce Soviet control in its agreed sphere of influence. The USSR demands Bessarabia from Romania, which refuses. The Red Army shortly thereafter invades across the border into river-laced, marshy country. Romanian troops aggressively counterattack Soviet columns slowed by blown bridges, mud, rivers, or swamps. Chaos reigns as Soviet troops are bogged down and picked apart, with muddled command decisions leaving active Soviet units directionless. The Summer War has become a massive, public humiliation for Soviet strength.
-Finland and Lithuania balk at Soviet demands in negotiations as apparent Soviet strength is nothing more than a paper tiger.
-Germany offers to "mediate" between the clumsy Soviet Behemoth and the Romanian hedgehog, with a "courtesy visit" of Luftwaffe elements to Bucharest and Ploiesti sending a not-so-subtle signal.
-Japan takes stock of the situation, the government fully aware that current trends cannot continue. Drastic change must occur, else Japan will be effectively bankrupt and unable to trade at all, or run out of strategic materials and lose all gains made in China, among other unpleasant possibilities. Desperate negotiations occur with the US, but are increasingly viewed as hopeless.
-Japanese Hawks view late 1940 as a window of opportunity for a successful war. The UK and Allies are locked in a life-and-death struggle with the Axis powers, which demands most British aeronaval power given the threat of invasion. The USSR is viewed as a house with an entirely rotten foundation, and a craven interest in peace. The United States is still building up its army and navy, but will not become relatively weaker in the future given vastly greater American production. The best answer to the dilemma, say Japan's hawks, is to gain quick victories and negotiate a favorable peace...
-The last of the negotiations between the US and Japan fail, and the hawks take control. War is prepared and launched...
So, that's about what I'm thinking could work. I just dashed this off, so presumably there are a large number of things wrong with it. That said, I think it's pretty clear my intentions to "force" Japan to choose 1940 for war for economic reasons, while the strategic picture could potentially allow for a negotiated success given the weakness of other powers involved. Thoughts?