The Vietnam War was a testing ground for American military technology.
But one particular operation received significant funds... and was kept a very big secret.
From 1968 to 1973, the military spent nearly $1 billion a year on a modern, computer-powered
initiative to win the war.
As most secret operations do, the plan went by many names, including Practice Nine, Muscle
Shoals, Illinois City and Dye Marker.
Today it's known as Operation Igloo White.
For almost five years, camouflaged electronic sensors, which were supposed to look like
artificial vegetation, were dropped along the nearly 10,000 miles that comprised the
Ho Chi Minh Trail.
These secret electronic monitors detected and transmitted enemy movements along the
Trail to aircraft that patrolled the area.
The pilots would then relay the data to air bases in Thailand.
Targeted strikes, however, wouldn't occur then and there.
Instead, the data was fed into two supercomputers in a 200,000-square-foot facility to generate
predictions about where along the Ho Chi Minh Trail the Viet Cong would appear next.
It was the first real-time, computer-driven surveillance operation program set up for
combat.
And it was hoped that it would be the U.S. military's own version of "The Minority Report"...
The Threat
The Ho Chi Minh Trail was a network of supply routes nestled under the cover of vast jungle
terrain.
The rainforest density allowed the Viet Cong to deliver war materials and supplies from
the Northside of the country to the South, all while hiding from the American eye.
Many of the routes, used for centuries by locals, were made out of mostly dirt.
As the war progressed, they were then expanded and built up, usually with gravel or pavement
surfaces.
Where gaps existed in the rainforest canopy, artificial camouflage was used to hide the
roads.
The Vietnamese and their allies constructed local base areas as storage nodules in this
extensive and intricate network.
These were often equipped with safe shelters, bunkers, and even hospitals and command sites.
By 1968, more than 40,000 people were committed to the construction, maintenance, and operation
of this vast resupply network.
The United States recognized early in the Vietnam campaign the relevance of the Trail.
Use of the route increased further as the U.S. Navy cut off coastal traffic used for
smuggling and the U.S. Army closed-off land routes through the Demilitarized Zone.
To add further geopolitical complications to the U.S.'s strategy, most of the Ho Chi
Minh Trail was located in Laotian territory, a supposed neutral zone.
A bombing halt over North Vietnam in 1968 marked the end of the Rolling Thunder era
and signaled a change in the direction of the war.
The bombing effort's focus then shifted to the destruction of and interdiction of the
Ho Chi Minh Trail.
Igloo White
In 1966, the United States' Secretary of Defense Robert McNamara wanted to study all available
war tactics in hopes of creating alternative solutions to increasingly indiscriminate bombing
strategies.
He recruited a group of prominent American scientists, and, out of all the solutions
proposed, McNamara chose electronic surveillance technology.
With the specific mission of developing modern sensor technology, McNamara established a
new task force.
The sensors needed to be capable of operations in the unrelenting heat, dense jungles, and
monsoon seasons.
The new organization's name was the Defense Communications Planning Group, or DCPG, part
of the Department of Defense.
The DCPG's leader was Lieutenant General Alfred Starbird, from the U.S. Army.
Starbird brought together technical experts from several U.S. government agencies and
governmental laboratories to send the sensors to Southeast Asia.
The plan, dubbed Operation Igloo White, called for delivering the monitoring devices along
the Ho Chi Minh Trail to detect enemy movements.
The operation began in 1967 when the taskforce officially started building a static sensor
tripwire across the Laos panhandle and the northwestern border of South Vietnam.
Several thousand sensors were dropped by aircraft throughout the anti-infiltration zones during
Igloo White to detect enemy foot or vehicular movement.
Some sensors detected seismic movements caused by passing trucks, and others used microphones
to pick up nearby voices.
One model was even able to chemically sense sweat and urine.
Each of the sensors came with their own set of problems.
For example, the metal detecting sensors couldn't tell the difference between a gun and a shovel.
And although it could alert movement, the seismic movement sensor couldn't know whether
it was from an actual enemy vehicle.
Installation
To place the Igloo White sensors, F-4 Phantoms, CH-3 helicopters, and other similar aircraft
dropped the devices by air.
These were designed to look like foliage that struck the ground like lawn darts, burying
themselves up to their antenna.
The acoustic sensors were delivered by camouflaged parachutes and would latch on to tree branches.
All sensors in operation were autonomous.
They were already equipped with their own battery packs and transmitters.
Still, they died down after a couple weeks, so replacement sensors had to be dropped in
the same area.
In Operation Igloo White, sensors weren't the only item dropped from the sky.
To help their acoustic sensors hear movement in the jungle, the military also began dropping
"acoustic mines."
These artifacts made a loud noise when anyone stepped on them.
Though they were harmless, it is believed that the military also dropped actual landmines
in this operation.
Steve Lukasik, deputy director and later director of the Defense Advanced Research Projects
Agency from 1967 to 1974, mentioned [QUOTE]: "They were devilish little mines.
They were mines you stepped on [...], and they had this whole range of what we would
now call cluster bombs.
Except they weren't clustered bombs, they were cluster mines."
Center
After installation, orbiting aircraft, such as the EC-121R Batcat, worked together with
signal relay platforms and navigation systems to monitor the sensor fields and transmit
their data to the Infiltration Surveillance Center, located in Thailand.
At nearly 200,000 square feet, this Center became the most prominent building in Southeast
Asia at the time, even though it was built in less than six months.
Security in the Center was very tight, and employees weren't allowed in all rooms.
The Center would process and interpret the data signals through two state-of-the-art
IBM 360-64 mainframe computers.
The base's personnel would notify combat commanders, who, in turn, sent the closest attack aircraft
team to neutralize the target.
The sensors placed on the Trail often aided in the interdiction of North Vietnamese supplies
and reinforcements.
For example, in December of 1970, a group of American pilots searching for hidden enemy
trucks and supply dumps received word that the sensors had detected heavy vehicle traffic
in their designated area.
This intelligence-led to discovering a large North Vietnamese Army storage unit near the
deserted village of Ban Bak in Laos.
Over that next week, U.S. airstrikes destroyed approximately 46 enemy trucks, 10,000 rounds
of ammunition, 1,000 tons of supplies, and countless drums of fuel.
Unforeseen Obstacles
When the North Vietnamese took notice of the Igloo White sensors, they began taking countermeasures.
The soldiers either destroyed the sensor or attempted to mess with the Americans by inducing
false reports.
In one case, the North Vietnamese drove cattle up the Trail and then hung buckets filled
with urine in the tree branches to foil the sensors.
On the other hand, Operation Igloo White hadn't taken into account one significant limitation.
New routes across the Ho Chi Minh trail were being built almost every day.
Even at the bombing campaigns' peak, the North Vietnamese would build up to two miles of
new roads per day.
This allowed North Vietnamese tanks to show up in South Vietnam, after having come all
the way down the secret Trail without being detected, much less stopped by the American
troops.
After years of denial, President Richard Nixon finally acknowledged publicly about the U.S.
military involvement in Laos.
Then, Igloo White came under considerable scrutiny.
The operation was also costly, as it cost around one billion dollars per year to manage.
The bombing operations cost that the sensors supported amounted to approximately 18.2 million
dollars per week, not including the hundreds of aircraft lost during the interdiction campaigns
or the crews that operated them.
After a four-year hiatus, the bombing campaigns in North Vietnam resumed.
Most U.S. airstrikes, which had been concentrated on the Ho Chi Minh Trail Operations, shifted
to North Vietnam targets.
U.S. Army objectives had also changed by then.
A primary goal of the bombing was to push North Vietnam toward a negotiated settlement
of the War.
The airstrikes then concentrated on Hanoi, Haiphong, and military centers in the north
to achieve this.
Igloo White operations on the Trail diminished in 1972 and then stopped altogether.
The computers at Nakhon Phanom were packed up and shipped back home to the United States.
A Successful Failure
There is continuing controversy in the U.S. regarding the practicality and utility of
the enormously expensive Igloo White operation.
Was it a success or a failure?
Detractors believe the program was far too expensive, and its utility waned as the Viet
Cong caught on to the sensor deployment.
When they finally realized what was happening, the North Vietnamese were quick to identify
hidden sensors, and they would perform sweeps of the areas in which they were found.
In particular, critics point to several successful late war offensives supplied by the Ho Chi
Minh Trail as evidence of the PAVN's adaptations to thwart the program.
The sheer volume of sensors dropped, however, made it impossible to completely eliminate
the surveillance threat.
Proponents cite the successful sortie rates, the verified bomb damage assessment results,
and point to the alternative of an unfettered flow of material from the North to the South.
The strategic impact of the resources consumed by the PAVN to maintain and defend the Trail
was also analyzed.
Although the commanders soured on the program towards the end of the war, more recent research
suggests that over 80% of the supplies sent down the Trail were destroyed.
What is clear is that Operation Igloo White remains one of the biggest specialized Intelligence
Surveillance Reconnaissance campaigns mounted to date.
The technology used in the sensors is used to this day.