The Philippines Invasion

[Pips]

The strategic planning process that preceeds any military action is (I find) quite fascinating.

The Japanese invasion of 1941 was quite straight forward, for several reasons. The island of Luzon was the primary target due to:
a) Manila, the capitol of the Philippines and seat of the government, was on this Island.
b) The bulk of the US and Philippino land forces were based around the Capitol.
c) The bulk of US air unis was on thius Island.
d) Luzon was the only Island that Japanese airc suport could cover, having to operate from land based airfields in Formosa.
e) Take Luzon, and the remainder of the Philippines would fall.

But the planning for the US recapture of the Philippines was far more involved and difficult. The Japanese had spread quite sizeable land forces throughout the Philippine archipelago, from Luzon in the north to Mindanao 1,200 kilometres in the south. The very nature of the powerful US forces, their control of the sea, the ability to strike with overwhelming force wherever they chose; offered such a range of choices that in some ways confused the issue.

Initially the US intention was to attack Mindanao and work there way up the Island chain. Finally the decision was taken to first land on Leyte, and progress from there towards Luzon.

Why was Leyte chosen? It has always struck me as an odd choice. It's bang smack in the middle of the archipelago, surrounded by Japanese occupied Islands with good airfileds on Cebu, Panay and Bacolod. And (on paper) the Japanese could funnel strong land and air forces from both Luzon and Mindanao. I have always thought that Samar or Mindoro offered better freedom of action.

Does anyone know the reasoning behind the Leyte choice?

[Tim Smith]

If the Americans have naval and air supremacy, then they can land on Leyte and bypass the smaller islands.

Due to massive carrier airpower, they can destroy most of the Japanese aircraft on the smaller islands.

With massive naval power, they can prevent or at least severely hinder the Japanese moving ground troops from the smaller islands to reinforce Leyte.

The Japanese land forces on the smaller islands are useless if they can't be transported elsewhere!

[Peter H]

Compared to Luzon,Leyte also did not have many fortified positions setup.

[JamesL]

A snip from the US Army Center for Military History - Carlisle Barracks.

"On 12 March 1944, the Joint Chiefs of Staff directed General MacArthur to plan an invasion of Mindanao, the southernmost island of the archipelago, starting on 15 November. The general responded in June with a two-phase operational plan which included the seizure of southern Mindanao on 25 October to serve as a staging area for a larger amphibious assault against Leyte three weeks later. Luzon, the largest island in the archipelago and the location of the headquarters for Japanese forces in the islands, would eventually have to be taken to secure the Philippines. However, Mindanao and Leyte had features that made them desirable, if not necessary, preliminary operations to the liberation of Luzon. For one, both islands were accessible. Generally exposed coastlines—Mindanao to the south and Leyte to the east—would allow American forces approaching from either direction to preserve uninterrupted lines of communication from recently secured bases. In contrast, an amphibious strike directly against Luzon in the northern Philippines would be more difficult to support. Second and critical to forces operating together for the first time, both islands were known to be defended by garrisons much smaller than that on Luzon. MacArthur's staff estimated Japanese combat strength on Mindanao to be 50,000 with another 50,000 in the Visayas, the central Philippine Islands which included Leyte. They estimated that Luzon had 180,000 defenders."


Gen. MacArthur had spent much of his career in the Phillipines and knew the land well. I gather that as a young officer he and his aide Dwight Eisenhower surveyed the landing beaches. There were also political considerations in liberating Manila as soon as possible.

I seem to recall that Gen. MacArthur's troops carried out over 80 amphibious landings.

[pitman]

Moreover, the Leyte invasion was possible because of the successful suppression of Japanese air power in the area.

[HMan]

Hastings claims that Leyte was unsuitable for airfields and was a poor
choice to launch an invasion against. This author is very anti-MacArthur,
so I am skeptical, but I wonder if anyone has an idea of the truth of this.

[Takao]

Hastings claims that Leyte was unsuitable for airfields and was a poor
choice to launch an invasion against. This author is very anti-MacArthur,
so I am skeptical, but I wonder if anyone has an idea of the truth of this.

Well, you left out the "during rainy/monsoon season" part...

Which, the Americans landed right smack dab in the middle of. The horrible weather also hindered the construction of roads and bases. As a result the build up of American power, especially air power, on Leyte got off to a very slow start. The poor conditions led to the Americans abandoning construction of airfields at Buri and San Pablo, before finally going with Tanauan - which did not become operational until December 16, 1944.

However, Leyte was not necessarily a "poor" choice for invasion. The speed up of the invasion of the Philippines did keep the Japanese off balance, and Leyte did have some very fine harbors that would come in rather handy. Still, the failure to quickly establish airbases and a decent logistical network did prolong the Leyte campaign.

[Kingfish]

Could geography and a healthy respect for IJN surfaces forces have influenced the decision to choose Leyte?

3rd fleet's emphasis on covering both San Bernandino and Surigao straits, both natural choke points for any IJN SAGs approaching from the west, seems to indicate so.

[HMan]

Hastings claims that Leyte was unsuitable for airfields and was a poor
choice to launch an invasion against. This author is very anti-MacArthur,
so I am skeptical, but I wonder if anyone has an idea of the truth of this.

Well, you left out the "during rainy/monsoon season" part...

Which, the Americans landed right smack dab in the middle of. The horrible weather also hindered the construction of roads and bases. As a result the build up of American power, especially air power, on Leyte got off to a very slow start. The poor conditions led to the Americans abandoning construction of airfields at Buri and San Pablo, before finally going with Tanauan - which did not become operational until December 16, 1944.

However, Leyte was not necessarily a "poor" choice for invasion. The speed up of the invasion of the Philippines did keep the Japanese off balance, and Leyte did have some very fine harbors that would come in rather handy. Still, the failure to quickly establish airbases and a decent logistical network did prolong the Leyte campaign.

So would anywhere in the Philippines have had the same problems
of being in the rainy/monsoon season? E.g. no matter where the
Allies landed in Oct. they would have had problems with construction?

[Delta Tank]

Kingfish,

What does SAG mean?

Mike

[Kingfish]

Kingfish,

What does SAG mean?

Mike

Surface Action Group

Basically any task force that is created to slug it out with main guns and torps.

Three of the four IJN groups would fit that bill. Ozawa's carrier decoy force was the odd man out.

[Pips]

As so clearly discussed above, by 1944 the Americans had almost total freedom (due to their overwhelming sea and air power) in their choice on the point of attack. But whatever their choice, ultimately they would have to confront the Japanese on Luzon. No doubt the Japanese command both in the Philippines and in Tokyo would have realised this.

Given that knowledge, why then did not the Japanese High Command not withdraw their (spread) forces from the lesser islands and concentrate them on Luzon? As Tim Smith mentioned above, the might of the USN would severely curtail Japan's ability to move troops from by-passed islands to main battle points once invasion started.

I'm certainly no strategist, but isn't force concentration a basic military premise? Weaker Japanese forces, compounded by distance and the inability to either support or reinforce, will not save Luzon. Luzon has be the climatic battlefront. Yes, having the American's battle lessor points first probably slowed the approach to Luzon - but the loss of valuable troops to the Japanese OOB surely had a greater negative effect on the Luzon battles than any benefits obtained in casualties suffered by the Americans battling at Leyte or other places.

[Kingfish]

As so clearly discussed above, by 1944 the Americans had almost total freedom (due to their overwhelming sea and air power) in their choice on the point of attack. But whatever their choice, ultimately they would have to confront the Japanese on Luzon. No doubt the Japanese command both in the Philippines and in Tokyo would have realised this.

Given that knowledge, why then did not the Japanese High Command not withdraw their (spread) forces from the lesser islands and concentrate them on Luzon? As Tim Smith mentioned above, the might of the USN would severely curtail Japan's ability to move troops from by-passed islands to main battle points once invasion started.

I'm certainly no strategist, but isn't force concentration a basic military premise? Weaker Japanese forces, compounded by distance and the inability to either support or reinforce, will not save Luzon. Luzon has be the climatic battlefront. Yes, having the American's battle lessor points first probably slowed the approach to Luzon - but the loss of valuable troops to the Japanese OOB surely had a greater negative effect on the Luzon battles than any benefits obtained in casualties suffered by the Americans battling at Leyte or other places.

The reason is oil.

Whomever controls the Philippines controls the LOCs from Japan to the Dutch East indies oil fields, and while Luzon is the best choice for interdicting the sea lanes, it is not the only one.

In a sense it is similar to the problem the Germans faced in pre-Overlord Europe. Their early success penalized them later on when they faced an opponent with overwhelming superiority in nearly all categories.

[LineDoggie]

Given that knowledge, why then did not the Japanese High Command not withdraw their (spread) forces from the lesser islands and concentrate them on Luzon? As Tim Smith mentioned above, the might of the USN would severely curtail Japan's ability to move troops from by-passed islands to main battle points once invasion started.

I'm certainly no strategist, but isn't force concentration a basic military premise? Weaker Japanese forces, compounded by distance and the inability to either support or reinforce, will not save Luzon. Luzon has be the climatic battlefront. Yes, having the American's battle lessor points first probably slowed the approach to Luzon - but the loss of valuable troops to the Japanese OOB surely had a greater negative effect on the Luzon battles than any benefits obtained in casualties suffered by the Americans battling at Leyte or other places.

The reason is oil.

Don't forget the Japanese military trait of stubbornness.

Other than Kiska, they rarely retreated while not under fire from an area they conquered. An almost animalistic territoriality and refusal to accept battlefield reality marked their operations after 1942

[OpanaPointer]

I just finished transcribing Halsey's AAR regarding Cape Engaño and the Taffy 3 battle. Fun reading.