Frontier War
| Frontier War | |||||||
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| Part of the East Indies Crisis and the Silent War | |||||||
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The Frontier War was a military conflict between the Union of Soenda and the Free State of Pinang, which broke away from Soenda following the decolonization of the Dutch East Indies and the East Indies Crisis. The conflict ended in a stalemate, with Soenda unable to subdue Pinang, which received diplomatic support and recognition from China.
Background
Dutch withdrawal in the East Indies Crisis
The origins of the conflict can be traced to the waning months of the East Indies Crisis, during which Dutch forces began their withdrawal from the East Indies. This caused a feeling of abandonment within the Royal Netherlands East Indies Army (KNIL), resulting in numerous units rebelling or going into hiding. The final departure of the last Dutch vessel from Batavia was on November 11, 1976, leaving behind the rogue KNIL units.
Establishment of the Free State of Pinang (1976)
Amid this chaos, KNIL's Captain-General Middendorp, based in Pinang, saw an opportunity. Throughout the final days of the war, he maintained contact with his connections in the Netherlands, other officers across the East Indies, and the local Chinese Kongsi in Pinang. With their help, he managed to secure supplies, additional units, and resources to sustain a prolonged campaign against the incoming Soendanese Liberation Army (SLA).
Officially, this effort was to manage the influx of refugees into their area of operations in Pinang, many of whom were Chinese, Dutch, Eurasian, and various other groups targeted by the SLA. Middendorp viewed the Dutch government in The Hague as ineffective, if not neglectful. Middendorp, in cooperation with the Kongsi council in Pinang, declared the formation of the Free State of Pinang, (Dutch: Vrystaat van Pinang, Chinese: 自由邦檳城) on October 1976, and he was immediately elected as the temporary supreme commander of its armed forces. This declaration of independence came shortly before the fall of Batavia to Soendanese forces.
Upon hearing of Pinang's establishment, Soenda was determined to eliminate it along with other rogue KNIL holdouts, such as the Borneo Republic, despite multiple mounting pressures such as emerging tensions with the Philippines and the need to rebuild their nation from the ground up. Soenda viewed Pinang as a remnant of the colonial power they had recently expelled.
When the Borneo Republic, another rogue KNIL state based in Koetsjing, Borneo, fell to Soendanese forces in late 1976, resulting in the massacre of Dutch, Chinese, and KNIL personnel, it reinforced Pinang's resolve. The fall of Borneo showed the potential consequences for Pinang if it were to capitulate to Soenda.
Description
The conflict was intense and, at least from Soenda's perspective, undeclared, yet it was significant enough to cost them divisions of manpower and, by some estimates, delay national recovery by several years. The region surrounding Pinang was a mountainous hinterland with valleys and terrain well known to the KNIL. Many KNIL soldiers were battle-hardened, and their ranks swelled with additional disgruntled soldiers who were unwilling to cease fighting, as well as clandestine support from Tauland and elements of the Netherlands' military.
Small Pinangese teams entered the jungle to engage Soendanese forces. Numerous battles occurred, with the largest taking place in the first few months, including the siege of Battle of Gerik (December 1976), Siege of Taiping (February 1977), and finally, the Battle of Vriesstad (April 1978). During the latter battle, KNIL armored forces successfully pushed Soendanese attackers out of the region, securing Vriesstad for the first time in years. While battles were generally waged by light infantry and on a small scale, the conflict was also notable for its intense air battles. To this day, destroyed Soendanese aircraft can be found in the dense jungle.
At the end of the conflict, Major Lodewijk Nije Bijvank, a Netherlands-born officer who had been engaged in warfare in the East since 1963, remarked:
"It is only because the terrain is mountainous, the roads are few and underdeveloped, and that we honestly blew the bridges and tunnels... and I won't lie, we had the advantage in the air, and those damned guys were half distracted... that we have survived... by the skin of our teeth, we have survived.
— Lodewijk Nije Bijvank
Given the geographical and logistical and constraints, both sides only deployed small teams. The KNIL's success was attributed to their teams being composed of hardened veterans, coupled with shrewd political maneuvering.
Course of the war
Shortly after declaring its independence in October 1976, the military forces of the Free State of Pinang faced an assault by Soendanese forces. The attacks began on the 5th of November, when a squadron of Soendanese fighters attempted a raid on Willemshaven. Pinang's radar systems detected the raid, and it was intercepted by the Free State’s air patrols. This marked the beginning of the conflict.
The Gerik Corridor
Soendanese infantry, supported by armor and artillery, captured the town of Gerik, a critical road junction leading to the heartland of Pinang. The fall of Gerik posed a direct threat to the Free State, as it left the route to the interior vulnerable unless the tunnels and bridges were destroyed—an option the KNIL could not afford to risk.
Battle of Gerik (December 1976)
With the capture of Gerik, the road to Vriesstad and Willemshaven lay essentially open. In response, the Free State acted swiftly, deploying the 58th Battalion "Huzaren van Bernard," under the command of Colonel van Veen, to Gerik. The battalion consisted of nearly 34 armored cannons, 70 armored vehicles, and a total of 930 soldiers. Within hours, the battalion reached the outskirts of Gerik, where they immediately encountered heavy Soendanese artillery fire.
The 58th Battalion established a defensive perimeter to prevent the Soendanese forces from advancing further into the Pinang heartland. Despite the initial resistance, the battalion came under intense artillery fire, followed by an infantry assault that was successfully repelled. As night fell, Colonel van Veen ordered a company to move through the jungle and flank the Soendanese forces, catching them off guard and inflicting significant damage. The Soendanese quickly responded, but this maneuver served as a distraction, allowing the remainder of the battalion to launch a coordinated attack with air support.
The battle raged throughout the night and into the following day, with the 58th Battalion ultimately driving the Soendanese forces out of Gerik. Despite securing the town, the Vrystaat forces faced relentless artillery barrages from the Soendanese. The 58th Battalion, suffering heavy casualties, dug in to hold their position. Over the course of a week, the town was nearly destroyed, but the battalion’s defense bought enough time for reinforcements to arrive and for the Free State to repel other Soendanese incursions. During this time, hundreds of thousands of refugees who had gathered in Gerik were able to flee into the Pinang heartland. Eventually, the Soendanese forces withdrew from Gerik as they shifted their focus to a larger offensive against Pinang. However, this offensive was hampered by the ongoing effects of the conflict, the need to secure other islands, and emerging tensions with the Philippines.
Siege of Taiping
Taiping, a city situated 23 meters above sea level on a plain west of the Bintang Mountains, lies 48 km southeast of Ipoh, the capital of the Soenda's Perak State. Due to its geographic location—close to Ipoh and flanked by the Bintang Mountains—it quickly became the gateway to the core of the Pinang Free State. Recognizing its strategic importance, the KNIL stationed the 7th Slag-Korps there in the final days of the East Indies Crisis. This force, consisting of six divisions, began fortifying the city as rapidly as possible, using the influx of hundreds of thousands of refugees as labor to dig trenches, build fortifications, and set traps to hinder any potential enemy advance through the narrow valley.
The General Staff, led by Kapitein-Generaal Willem de Vries, understood that if Taiping fell, the road to important population centers such as Willemshaven and Praaistad would be open. Command of the 7th Slagkorp was thus entrusted to Lieutenant-General Rikkert in 't Bouwhuis, a seasoned veteran of the Great War, the Djohor Uprising, and other conflicts involving the Netherlands in the early 20th century. Known for his resourcefulness under pressure and his defiance, which had seen him promoted as often as demoted, in 't Bouwhuis was deemed the right man for the job given the precarious situation: no reinforcements, limited supplies, and an enemy that outnumbered them nearly seven to one.
He assumed command on February 1, 1976, just in time, as on February 3, 1976, the Soendanese National Army launched its first assault on the Taiping.
1st siege of Taiping
The siege began on February 3, 1976, at 09:43 local time, when the first shells began raining down on the city. Fired from positions near Ipoh and within the Bintang Mountains, the bombardment lasted seven hours. The Free State forces, hunkered down in their fortifications, withstood the shelling. However, the real attack followed the bombardment, as the 4th Mechanized Guard Division, supported by air elements, assaulted the damaged fortifications defending Taiping.
Despite being well-coordinated, the Soendanese attack was ultimately repelled. Anticipating the assault during the bombardment, the defenders were ordered to hold their positions and prepare for the onslaught. The Soendanese attack was said to have almost destroyed Pinang's 4th mechanized guard division, which was still in its infancy, as it tried to breach the Pinangese defenders' 'kill zone' that surrounded Taiping. Although the assault failed to achieve its objectives, it revealed the locations of the Pinangese Landmacht’s defensive emplacements.
Despite success in repelling the attack, the defenders' hope that they had broken the Soendanese attack proved to be wrong. Later that week, under the cover of continued morning barrages, several companies of Soendanese irregulars infiltrated the city from the Bintang Mountains and launched a campaign of terror. The infiltration led to intense urban fighting, but the Korpscommandant responded swiftly by deploying "Territorial Defense Units." Supported by veterans of the war, these units routed the infiltrators and publicly executed them at the front line in full view of Soendanese soldiers and intelligence officers. The Korpscommandant’s brutality was on full display when he personally executed the captured infiltrators, an act that made him a marked enemy of the state of Soenda.
Resolution
Amoy Agreement (July 1979)
In the summer of 1979, as the conflict between Pinang and Soenda reached a critical point, the National Republic of China, a key diplomatic supporter of Soenda, grew increasingly concerned about the prolonged hostilities, particularly due to the presence of a significant ethnic Chinese population in Pinang. With Russian support for Soenda waning, China became the sole remaining traditional national republican power backing Soenda. Soenda became increasingly concerned about the potential loss of China's diplomatic recognition and support.
In July 1979, China initiated peace talks in Amoy, China, aimed at resolving the conflict. These talks were attended by representatives from Pinang, Soenda, China, and with Tauland acting as an observer. Despite the high stakes, the negotiations were kept low-key, with limited media coverage. The discussions led to what became known as the Amoy Agreement (Dutch: Verdrag van Eemoei; Chinese: 廈門協議 Hiamen hie-ie) a ceasefire that marked the end of active hostilities. The agreement is also colloquially referred to as the "off-camera handshake," referring to a rumored but unrecorded handshake between the Pinang and Soendanese delegations—a symbolic gesture that was witnessed by few and documented by none.
