"Paul J. Adam" wrote in message ...
From a very distant perspective, SIGINT folks seem to get jumpy about
their results being used tactically, sometimes with good reason: if
you've got a reliable way to eavesdrop on the enemy and you believe it's
of significant strategic value, is it worth compromising it for a
short-term tactical advantage? Sometimes this approach is justified:
perhaps other times it may be reflex rather than reason.


Intriguinly, the USAF seemed to have much less trouble utilizing this
sort of information during the Korean war then during the Vietnam war.
Wonder what the difference was?

from: http://www.nsa.gov/korea/papers/sigi...korean_war.htm

"Air Force Support
The Air Force Security Service continued support to the air during the
period of stalemate. The AFSS also adopted a number of innovations to
provide new kinds of support for the air war.

A good example of AFSS support occurred in June 1951. Analysts at an
Air Force intercept site were able to accurately predict a North
Korean bombing raid on UN-held islands. This intelligence enabled the
commanding general of the U.S. 5th Air Force to ensure that the raid
was met with ample defense. one YAK and two IL-10 bombers were downed,
several others were damaged, and two MiG fighters were also damaged.
It is believed that the commander of the 5th Air Force may have been
aware of the impending raid before the commander of the North Korean
attacking unit had received his orders.

In late April 1951, AFSS personnel intercepted messages that indicated
aircraft of the 4th Fighter Squadron were being boxed by Soviet
aircraft. The quick relay of this information to the flight enabled it
to avoid the trap. This kind of warning continued through the war.

Soviet Bloc Air defense doctrine called for control of local fighter
pilots by their tower. These ground control intercept (GCI)
communications were vulnerable to eavesdroppers.

At various periods during the air campaign, COMINT units from the AFSS
were intercepting North Korean, Chinese, or Soviet instructions to
their pilots. These were disguised as "radar plots" and forwarded in
near-real time to U.S. pilots operating over North Korean territory.
When this source was exploited, the U.S. "kill ratio" over MiGs was
quite high; during periods of nonexploitation, the ratio was much
lower.

Monitoring of North Korean, Chinese, and Soviet air communications was
done from listening posts in South Korea, but there were hearability
problems for certain areas at different times of the day. To solve
these problems, in mid-1951 the AFSS established an intercept site on
Paengyong-do - commonly known as "P-Y-do" by Americans - a UN-held
island close to the west coast of North Korea. Since this was close to
enemy territory, the security regulations had to be relaxed, and 5th
Air Force had to provide special evacuation service. Eventually the
Americans abandoned their effort on the island.

Once this activity on P-Y-do proved successful, in the spring of 1952
a similar operation was undertaken on Cho-do, a UN-held island off the
east coast of Korea, near Wonson. Lieutenant Delmar Lang organized
teams of linguists and personnel from the Tactical Air Control Center
to provide near-real-time information to pilots operating over North
Korea. Del Lang, by the way, used this operation as a model for
similar activity during the Vietnam War.

Security Service also conducted airborne collection operations. In
addition to support of the war effort, these flights were useful in
testing intercept equipment and general concepts of operations."

Chris Manteuffel