Technology invades the modern world

Chapter 434 The Great Wall's Rescue

America's relentless attacks over the past six months have finally met their first reef today in Ashao Valley, Guangnan.

Such a casualty ratio was clearly unacceptable to America's army.

That's only a few missiles.

If 20 missiles were fired, they could cause three helicopters to crash and two to be seriously damaged.

That war cannot continue.

North Vietnam originally relied mainly on the SA-2 Compass surface-to-air missile system from the Soviet Union.

This is also the core of North Vietnam's air defense system.

According to America's postwar report, "Air Combat Report of the Vietnam War," when North Vietnam used this system, it launched approximately 9000 missiles and shot down about 200 US aircraft.

The casualty ratio was 45 to 1.

The score is now 4 to 1.

Efficiency increased tenfold.

When the news reached America's command post in Saigon, McNamara realized from the direct reaction of the data that things had changed.

This is something that the Soviet Union's compass could never have done.

The duty intelligence officer pushed open the door to the operations room and, pale-faced, handed McNamara an encrypted telegram.

"Your Excellency Minister, this is Assaugu's report."

Our air formation lost five aircraft, and the navigation satellite system signal failed at a critical moment.

"These weren't conventional air-to-air missiles; they said the North Vietnamese missiles this time seemed to have eyes, predicting our movements!"

McNamara narrowed his eyes, pushed up his black-rimmed glasses, and stared at the data table on the telegram: flight path coordinates, electronic countermeasures activation time, and missile trajectory estimation.

The table was hastily drawn in pencil.

In McNamara's eyes, numbers speak for themselves.

With 20 missiles, the hit rate was as high as 50%, and the jamming intensity exceeded the known parameters of Soviet-made missiles.

One more thing to add: 20 bullets hit five planes; it wasn't a one-to-one ratio.

It's not that a missile can only hit one aircraft.

In reality, it's possible that multiple missiles hit the same aircraft.

In other words, of the 20 Dragon Shadows fired by China, 10 hit the target.

This number is quite astonishing.

“This is something the Soviet compass could never do,” McNamara murmured. “It would take dozens of Soviet missiles to hit an F-4 in a salvo, but here, 20 missiles tore our entire formation apart.”

Looking at this yaw data, their interference is targeted at our navigation system.

Satellite positioning should have been our trump card, but it hasn't been able to play its role.

In the operations room, the map wall was covered with colored pins, and the arrows representing the advance of the US forces paused for the first time in the Ashau Valley.

McNamara stood up, walked to the blackboard, and quickly sketched a simple chart with chalk.

He turned to his assistants and said, "This is definitely not luck."

Things are fundamentally changing.

Assemble the team and get the ground troops moving forward. We need to immediately send ground troops to search for the missile debris from this enemy mission. We need further information.

Those fragments are the best clues.

Before departing for Saigon, at a White House meeting with Nixon, McNamara urged the president: "The Vietnam War is not a hand-to-hand combat war; we must turn it into a battlefield of algorithms."

We have RAND Corporation, Bell Labs, IBM, Texas Instruments; what we're going to do is conquer the jungle with mathematics.

Nixon eventually agreed.

It's hard to imagine what magic McNamara possessed that allowed him to convince two consecutive presidents with his arguments.

Therefore, McNamara brought a large number of IBM System 360 series mainframe computers with him when he went to Saigon.

In addition, a team of professional engineers from IBM was brought in, and a large number of civil servants with mathematics expertise were transferred from federal agencies.

They took all of these people to Saigon.

For McNamara, the only regret was not being able to bring Lin Ran along.

However, he did bring along a mathematician, Zhou Yuanshen, a professor of mathematics and computer science at Columbia University.

McNamara was choosing between Zhou Yuanshen and Chen Jingrun, partly because Chen Jingrun worked in number theory, and statistics would be more in line with his desired direction.

After all, not everyone is Lin Ran, an all-rounder in the field of mathematics.

In addition to being a professor at Columbia University, Zhou Yuanshen is also a researcher at IBM's Thomas J. Watson Research Center.

On the other hand, Chou Yuan-shen is a pro-ROC mathematician who once served as an assistant professor at National Taiwan University, while Chen Ching-run has never expressed his stance in public and teaches at a left-leaning university such as the City University of New York.

So McNamara ultimately chose Zhou Yuanshen and brought him to the front lines.

In short, McNamara saw this as a replacement for the professor: a mathematician, of Chinese descent, a Columbia professor—okay, you're the one.

Upon arriving in Saigon, the engineers expanded the temporary analysis center that had been built in the basement of the military assistance command.

The walls were covered with flowcharts, and the air was filled with the sounds of fans and FORTRAN code printing.

McNamara's order was swiftly issued: a reinforced company of 150 soldiers from the 1st Cavalry Division, equipped with M16 rifles, radios, and GPS positioning equipment.

They advanced to the crash site in Ashau Valley under helicopter cover.

In the jungle, soldiers trudged through the mud, their boots soaked by the rain, wary of any possible ambush.

Company Commander Lieutenant Tom Harrison whispered the order: "Spread out and search, prioritize missile debris, avoid explosives, and mark the locations."

Two hours later, they found the first piece of debris in the scorched earth: a twisted aluminum circuit board with etched patterns on its surface, and a section of an antenna.

The soldiers carefully packed the items into canvas bags and airlifted them back to Saigon.

“Minister, our preliminary models show,” reported Harris Weber, IBM’s team leader.

His beard was disheveled, and his eyes were bloodshot from working on the project all night.

Being sent to Saigon was bad enough.

If it weren't for the fact that this was a White House order, personally assigned to him by an IBM vice president, and given ample leave, he wouldn't have been in this situation.

Harris Webber would never have come to this godforsaken place.

Fortunately, things had been progressing well. McNamara had privately told them many times that they would be able to end this damn war before Christmas, and that they would return home with honor and spoils for Christmas.

But the recent incident has put everyone on edge.

If the US military loses air superiority, is it still the US military?
As this war is about to return to a brutal, cutthroat mode, it's uncertain whether they can even win, let alone end it this year.

"Based on the radar echo data from these debris, the missile's seeker is not purely infrared; it has analog adaptive filtering and can switch frequencies within milliseconds."

Our satellite positioning signal was interfered with, and the error jumped from the centimeter level to the meter level.

Without a doubt, within the socialist camp, only China's semiconductor technology can achieve such silicon-based circuit density.

Only they can catch up with our AN/APQ-120 in the semiconductor field.

The AN/APQ-120 is a fire control radar manufactured by Westinghouse Electric for the McDonnell Douglas F-4E Mirage II. It is an all-solid-state radar that is compact enough to be mounted in the nose along with a cannon.

Throughout the Vietnam War, America's electronic warfare technology developed rapidly.

Large-scale operations began during the Rolling Thunder campaign in 1965, where they carried external pods on aircraft that emitted noise and deceptive signals to confuse enemy radar lock-on.

Waveform technology allows aircraft to generate signals at specific frequencies to simulate false targets or overlay real signals.

It also carries an onboard receiver to detect enemy radar signals, allowing pilots to take evasive action in advance.

In addition, they will deploy chaff to create radar clutter and distract missiles, and use heat decoys to counter infrared-guided missiles.

America's electronic warfare technology is rapidly maturing.

On the Soviet side, starting in 1967, their electronic intelligence experts and equipment also had to be deployed to maintain the balance of power on the battlefield.

The current situation is that the advent of GPS disrupted the balance in the past, and China's new missiles are attempting to restore it.

Weber pointed to the charts projected on the projector: one curve represented the trajectory of the Soviet-made missile; the other was the firing path of the Dragon Shadow.

The latter accurately predicted the American aircraft's right turn to evade it.

The integration of hundreds of transistors on a circuit board demonstrates the maturity of its technology.

McNamara nodded and tapped the table.

“Model it.”

The Monte Carlo simulation was run 1,000 times. Variables included wind speed, electronic countermeasures intensity, and satellite signal redundancy channels.

"Find the weaknesses." The engineers immediately sprang into action.

The following morning, McNamara convened a meeting with the frontline commanders.

The generals sat around a long table.

"Gentlemen," McNamara began, "we are not facing guerrillas, but technological advancements."

The Chinese intervened, and their missiles were deployed.

McNamara then issued a report: "Based on engineers' simulations and wreckage analysis, we should immediately adjust our tactics, switching the B-52s to high-altitude blind drops to avoid reliance on low-altitude satellite positioning; F-4 formations should be reinforced with Wild Weasel escorts to prioritize suppressing enemy radar; at the same time, more EA-6B electronic warfare aircraft should be urgently airlifted from the mainland, equipped with newly programmed jamming pods that can generate white noise against analog filters."

“The president has approved it,” McNamara added, “that we will extend the data link to every aircraft, providing real-time feedback on loss rates and optimizing flight paths.”

The Pentagon will provide us with the latest analysis in real time.

Our intelligence needs to be relayed to every frontline pilot.

In addition, we need to continue sending the army to search for more wreckage; every piece of debris is intelligence.

The intelligence sent back to the Kremlin included not only information about the Dragon Shadow surface-to-air missile, but also a request from China.

China wanted to take over part of the air defense on the North Vietnamese front.

In the past, this part of the work was always handled by experts sent to the front lines by the Soviet Union.

In fact, China had long wanted to take over.

They wanted to test their radar, or even the entire system, on the front lines of the Vietnam War.

It had been more than eight years since Lin Ran obtained the US military radar-related technical data (Christmas Day 1961).

In the past eight years, China has developed its own complete radar system.

After the initial test of its surface-to-air missiles, China is eager to use this opportunity to test and adjust its weapons and equipment, and to find directions for future optimization.

It's just that we couldn't find a suitable excuse in the past. The Soviet Union was doing a good job, so why should we replace them?

Now, the excuse has come up.

Soviet equipment was initially able to compete with America's, but America's advantage lay in their rapid research and development and fast iteration speed.

According to Bernard Naldi's "Tactics and Techniques of Electronic Warfare: Electronic Countermeasures in the Air War Against North Vietnam, 1965–1973," this is one of the American Air Force's series of tactical and technical monographs on Southeast Asia. The Soviet Union began to fall behind America's pace in 1970.

(An American Air Force F-105D Thunderchief attempts to evade a V-75V SAM launched from North Vietnam's SA-750 Dvina. Image courtesy of the American Air Force)

The Vietnam War tested the latest developments in electronic countermeasures by both sides.

Initially, radar-controlled surface-to-air missiles and anti-aircraft guns had an advantage.

However, the American Air Force improved the fighter-bomber's counter-pods and equipped and armed the aircraft to pinpoint and destroy missile bases.

These efforts, coupled with long-range jamming and countermeasures from other military branches, successfully restored a balance in favor of the offensive.

The original timeline became outdated starting in 1970.

It culminated in the B-52 attacks on the Hanoi-Haiphong region by Linebacker II in December 1972.

The entire wartime experience was compressed into a few days, and America completed the bombing.

But now, that time has been moved forward.

Now, the US military's advantage comes not only from GPS, but also from overall technological advancements.

The Soviet Union's air defense system was severely hampered by America's defenses.

The North Vietnamese front is in dire straits.

After Longying's initial foray into air defense, North Vietnam also expressed high expectations for China's air defense system and radar equipment.

In the Kremlin, Leonard leaned back in his chair, squinting as he smoked a cigarette.

Marshal Grechko, Gromyko, and several KGB officials were seated at the table.

The documents laid out in front of them were piled up like a mountain, mainly encrypted reports from Hanoi.

“Comrades,” Leonard began, “the comrades in Yanjing are causing trouble again.”

Intelligence indicates that they are not content with simply providing missile support; they now want to directly take over some of the frontline air combat.

They hope to deploy their air defense system in Lang Son province.

Their engineers wanted to teach their North Vietnamese comrades how to counter America's air force.

Comrade Gromyko, what do you think?

Gromyko adjusted his glasses and opened the report.

"Comrade Leonard, this is a thorny issue."

The Chinese claim their technology can fill our gaps. See Nalti's analysis.

However, their surface-to-air missiles proved that they were indeed capable of doing so.

However, the motives of the Yanjing side were clearly impure.

They claimed to share semiconductor technology, and intelligence indicated that their semiconductor technology had caught up with America's Bell Labs.

If they take over the air defense zone from Lang Son to Ashao Valley, North Vietnam will become more dependent on China.

This is not good for us.

Finally, Gromyko added, "Perhaps it will be advantageous to the situation in the Vietnam War."

After a moment's thought, Leonard said, "We cannot oppose it publicly."

The comrades in North Vietnam need assistance. America's progress is too fast; their overall technological advancements include not only satellite positioning but also those wild weasels and long-range jamming aircraft.

If the Chinese could delay the other side's iteration and allow our SA-2 to last a few more months, perhaps by 1970, our new SA-3 could catch up.

But the risks are high. If the Chinese succeed, Hanoi will turn to Beijing; if they fail, America will advance even faster, and our reputation will be ruined.

Gromyko nodded: "I suggest we negotiate with Yanjing privately."

Let them provide us with the technology to upgrade our equipment, and we will continue to lead the aid effort.

They publicly supported their intervention, but emphasized the unity of the camp.

We need Chinese technology to drive our multi-service cooperation; semiconductor technology is extremely important.

By 1969, leaders of major countries had realized the importance of semiconductor technology.

They simply lack a clear enough concept of just how important it is.

Now, judging from the electronic warfare on the front lines of the Vietnam War, it seems to be even more important than they thought.

At the conclusion of the meeting, Leonard finalized the resolution: "Send a telegram to Hanoi to welcome the supplementary assistance from our Chinese comrades."

But monitor them, Andropov, send more men to Hanoi; we need to find a way to acquire Chinese technology.”

One after another, secret transport planes landed in the valleys of Lang Son province. What they unloaded from the cabins were no longer isolated missile boxes, but an entire air defense system: twenty modified trucks carrying China's latest radar stations and electronic countermeasures equipment.

This time, the Chinese team leader, Engineer Li, appeared again, bringing more technicians with them. Their toolboxes were filled with transistor components and spare vacuum tubes.

“Battalion Commander Ruan,” Engineer Li unfolded the blueprint and explained to Ruan Wentai, “Dragon Shadow is just the blade; the Great Wall System I brought this time is the shield.”

This system includes three core pieces of equipment: the first is the Eagle Eye Pulse Doppler radar station, which is about the size of a truck and can scan in the S-band and X-band with a detection range of up to 150 kilometers.

It can track multiple targets and distinguish between US military aircraft and chaff clutter, with an error of less than 2 kilometers.

Unlike Soviet-made radars, it features analog adaptive filtering, enabling it to automatically switch frequencies to avoid interference signals from the US military.

Nguyen Van Thai nodded, and his soldiers gathered around, their faces full of curiosity.

The second device on the blueprint is the EW-1 area jamming vehicle, a platform disguised as a supply vehicle, equipped with a low-power transmitter and receiver array.

EW is an abbreviation for Electronic Warfare.

The core of this vehicle is an aluminum-cased circuit module that can generate white noise interference to counter the electronic countermeasures of the US military.

"It's not just passive defense," Engineer Li emphasized. "Our circuitry has a feedback loop that can detect the strength of enemy signals and then simulate false target echoes, filling their radar screens with ghost images."

Countering America's Wild Weasel mission? We can, in turn, lock onto their jamming sources and use servo antennas to guide missiles in retaliation.

This method is comparable to that of the US military, and may even be superior in jungle environments.

The third piece of equipment is the integrated command center: an underground modular control room that connects all units.

It contains a simple oscilloscope and a mechanical recorder, and the screen can display multi-channel radar data in real time.

“It’s the brain,” Engineer Li explained, “The integrated circuit processes signal fusion, radar data, infrared signatures, and radio interception, all together optimizing the missile’s trajectory.”

In short, we have complete confidence in this system; after all, it's named after the Great Wall!

This marked the beginning of electronic warfare, and America had a new opponent.

(End of this chapter)