For Keith Willshaw...

But had few such resources. There were only 36 trained cryptographers
available and at any one time only a small number (2 to 5) was assigned to
JN-25

When Japanese fleet assembled during early Nov.JN25 became the top priority and
all resources,that included cryptographers too,were assigned to JN25 reading.

Evcen had JN-25 been cracked Pearl Harbor attack plan was never broadcast
in JN-25 or any other cipher and the fleet maintained complete radio
silence.

They did broadcast it indeed on Nov.25.
Japanase Task force broke radio silence at least 28 times during its voyage to
Hawaii.

n the Pacific was likely. This had already been surmised which is why
the carriers of the USN were delivering extra aircraft to Midway
and Wake in early December 1941


Thats the reason why Washington cancelled Halsey's plan and removed carriers
from Pearl Harbor only a few days before attack.
Washington knew exact date and exact name of target.
WAshington was interested in producing an shock and awe event,but not
interested in losing war with Japan.
Events unfolded only a couple of months later around Midway proved that
US-British calculations were sound indeed.

By moving carriers away from Hawai just a few day prior to attack Washington
(Stark)accomplished several goals at one time.

1)The force that might deter Japanese from making the attack was no longer
available
2)Even if they were not deterred,an off shore naval battle using carriers would
not produce desired shock and awe.effect.
3)The carriers were in safety for later missions (for example Midway) whereas
Japanese were allowed to bomb useless WWI relics in Pearl Harbor.

Yamaoto's biographer (Hiroyuki Agawa) served under him in
the IJN and is quite clear that orders for the attack were
hand delivered and extreme precautions taken within the
navy to avoid compromising the plan.

No,Sir attack order came by radio waves and it also included instructions about
how to proceed if diplomatic negotiations with US were concluded
succesfully.(No attack).
This dispatch read by British on Nov.25,Dutch by Nov.27.
When US read this message?
Its is still classified !!!.

No sir they were not, the data released from Bletchley Park
as written about in 'The Emperors Codes' by Michael Smith
makes it quite clear that neither nation was reading
JN-25 at that time. This is reinforced by the
"History of OP-20-GYP-1"


US intercepted acc.to NSA 26581 JN25B coded messages and were able to read 2413
of them.
Again according to 1946 naval inquiry 188 of them clearly indicated Pearl
Harbor as target.
Do you know a kind of radiowave that needs days or even weeks to reach
receivers a couple of thousand miles away?
Only problem now we mere mortals are not allowed to read them,except 30 or 40
of them as almost all of them were the subjects of NSA withdrawal notices.