Query: Weather restrictions on timing of Japanese strike south into SEA?

raharris1973

Gone Fishin'
Donor
Monthly Donor
Perusing through the book - Pearl Harbor, the Missing Motive, by Kevin O'Connell, he asserts a few times that any Japanese assault on Southeast Asia would have to begin in December instead of January, Feb or Mar, because the rainy season starts with the turn of a New Year, so flying weather would not be good enough for carrier operations and other air offensives.

Do you buy that weather in early December is permissive of carrier operations while it becomes prohibitive in Jan, Feb or Mar? Why?

The concept does not seem to compute for me. It's not like Japanese carrier, air and invasion ops all started and finished in early December 1941. Rather they started in early December 1941 and continued through March and May 1942. It took some time to do all the landings, suppress all the enemy airfields, capture the enemy ground troops and occupy the territory. This involved air operations all along, so it does not seem like weather grounded air forces for weeks or months on end in Jan-Mar 1942.

Am I wrong here?
 
War Deliberations

Amidst this atmosphere of high tension, the Emperor on 6 September summoned the Cabinet and representatives of the Army and Navy High Command to a conference at which, for the first time, the question of peace or war was squarely posed. Deliberation centered upon an "Outline Plan for the Execution of Empire Policies " (Teikoku Kokusaku Suiko Yoryo), which provided:

1. In order to guarantee the existence and defense of the Empire, preparations for an eventual war against the United States, Great Britain and the Netherlands shall be completed approximately by the latter part of October.

2. Concurrently with the above, the Empire will exert every effort to secure realization of its demands through diplomatic negotiations with the United States and Great Britain. [The minimum terms which Japan would accept in an agreement with the United States were set forth separately.]

In the event that these negotiations fail to achieve the Empire's demands by the early part of October, it shall immediately be resolved to go to war with the United States, Great Britain, and the Netherlands.21

Speaking for both Army and Navy High
Commands, Admiral Osami Nagano, Chief of the Navy General Staff, backed up the plan with a warning that Japan's power to fight was steadily declining due to exhaustion of essential war materials and the increased military preparations of the ABCD Powers. Instead of " letting time slip idly by," he declared, the nation must first push its own war preparations and, if diplomacy fails, "advance bravely into offensive war operations." The statement was especially significant because it reflected the views of the Navy, the role of which would be of paramount importance in war with the United States. Essential extracts follow:22

The High Command sincerely hopes that the Government will exhaust every possible means of settling the present situation diplomatically. However, if Japan should be obliged to resort to war, the High Command, from the standpoint of military operations, is of the opinion that the gradual exhaustion of most of the country's essential materials such as petroleum, is lowering the national defense power, and that, if this continues, Japan in the end will fall irrevocably into a condition of impotency.

Meanwhile the United States, Britain, and other Powers are swiftly reinforcing their military establishments and strategic defenses in the Far East, and war preparations in these countries, especially in the United States, are likewise being greatly accelerated. Consequently, by the latter half of next year, the United States will be far ahead in its preparations, and Japan will be placed in an extremely difficult position.

Under such conditions, it is highly dangerous for Japan to let time slip idly by without attempting to do anything. I think that Japan should, first of all, carry out preparations as best it can; and then, if our minimum demands essential to self-defense and national existence are not accepted in the diplomatic negotiations and war finally becomes inevitable, we should not lose our opportunity but should advance bravely into offensive war operations with firm resolution, thus seeking the salvation of our country.

In regard to the outlook for such operations, it can be considered from the outset that the probability of an extended war is extremely great. Japan, therefore, must have the determination and the preparations to conduct an extended war. It would be just what we are hoping for if the United States, seeking a quick decision, challenged us with its main naval strength.

Considering the present position in the European war, Great Britain can dispatch to the Far East only a very limited portion of its naval strength. Hence, if we could intercept the combined British and American fleets in our own chosen area of decisive battle, we are confident of victory. However, even victory in such a battle would not mean the conclusion of the war. In all probability, the United States will shift its strategy to a long war of attrition, relying upon its invincible position and dominant material and industrial strength.

Japan does not possess the means, by offensive operations, to overcome its enemies and force them to abandon the war. Hence, undesirable as an extended war would be due to our lack of resources, we must be prepared for this contingency. The first requisite is immediate occupation of the enemy's strategic points and of sources of raw materials at the beginning of the war, thus enabling us to secure the necessary resources from our own area of control and to prepare a strong front from an operational viewpoint. If this initial operation succeeds, Japan will be able to establish a firm basis for fighting an extended war even though American military preparations progress according to schedule. For Japan, through the occupation of strategic points in the Southwest Pacific, will be able to maintain an invincible front. Thereafter, much will depend upon the development of our total national strength and the trend of the world situation.

Thus, the outcome of the initial operations will largely determine whether Japan will succeed or fail in an extended war, and to assure the success of the initial operations, the requisites are:

1. Immediate decision on whether to go to war, considering prevailing circumstances in regard to relative Japanese and enemy fighting strength;



2. Assumption of the initiative;

3. Consideration of meteorological conditions in the zone of operations to facilitate these operations.

It is necessary to repeat that the utmost effort must be made to solve the present crisis and assure Japan's security and development by peaceful means. There is absolutely no reason to wage a war which can be avoided. But to spend our time idly in a temporizing moment of peace, at the price of later being obliged to engage in war under unfavorable circumstances, is definitely not the course to take in view of the Empire's program for lasting prosperity.

i'd say the weather was considered, but not a deciding factor.
 

raharris1973

Gone Fishin'
Donor
Monthly Donor
notably, the statement you quoted doesn't mention weather or seasons at all. timing was important, but based on variables other than weather.
 
Perusing through the book - Pearl Harbor, the Missing Motive, by Kevin O'Connell, he asserts a few times that any Japanese assault on Southeast Asia would have to begin in December instead of January, Feb or Mar, because the rainy season starts with the turn of a New Year, so flying weather would not be good enough for carrier operations and other air offensives.

Do you buy that weather in early December is permissive of carrier operations while it becomes prohibitive in Jan, Feb or Mar? Why?

The concept does not seem to compute for me. It's not like Japanese carrier, air and invasion ops all started and finished in early December 1941. Rather they started in early December 1941 and continued through March and May 1942. It took some time to do all the landings, suppress all the enemy airfields, capture the enemy ground troops and occupy the territory. This involved air operations all along, so it does not seem like weather grounded air forces for weeks or months on end in Jan-Mar 1942.

Am I wrong here?


Hmm, well you could argue that if they started later, the monsoon would arrive before they finish conquering everything they conquer OTL.
 
Top