The Rainbow Regiment: the Batangueño Guerilla Group in WWII

In two earlier articles, I wrote about the exploits of the Hunters/ROTC, a guerilla group that was formed in the province of Rizal but relocated its headquarters to Nasugbu as the liberation of Luzon by Allied forces neared in 1944. But there was another guerilla group operating in Batangas, one that was organized by Batangueños and composed also of Batangueños. This was the Malakas Division of the AUSA (Army of the USA), otherwise known as the Rainbow Regiment.

The regiment was formed around May 1942, a few months after Miguel Ver formed the Hunters/ROTC group in San Juan, Rizal. It was organized in western Batangas mostly by escaped personnel of the USAFFE (United States Armed Forces in the Far East) and patriotic civilians.

The initial organizers of the regiment were all from western Batangas: Major Rodolfo G. Bahia, Major Amador Deguito and Major Jose T. Unson, all from Balayan; and Major Vicente Calingasan from the nearby town of Tuy. The group’s natural leader was Colonel Mariano H. Cabarrubia, originally also from Balayan but at the time a resident of Nasugbu.

When he organized the guerilla group in Nasugbu, Cabarrubia had just returned from Capaz, presumably having been part of the infamous Death March. Before the Japanese occupation of the country, he was an officer in the Philippine Constabulary of the Commonwealth of the Philippines. In anticipation of war with Japan, the United States absorbed Filipino military troops into the USAFFE, in which Cabarrubia rose to the rank of Captain¹.

Among the new guerilla group’s earliest priorities was to affiliate itself with the Filipino-American Irregular Troops (FAIT). The FAIT was a guerilla group organized by retired American Colonel Hugh Straughn, who would be captured and beheaded by the Japanese in August of 1943. This group was made up of Filipino and American soldiers who refused to accept the 1942 surrender of USAFFE forces to Japan².

In August of 1942, Deguito traveled all the way to the Sierra Madre Mountains, where the FAIT guerillas were in hiding, to contact Straughn. His trip was fruitful because he was given authorization to organize guerilla resistance in western Batangas, to be affiliated with the FAIT.

All the while, the organization continued to accept and train volunteers, naturally after careful screening since many young men wanted to join up. The guerillas were also careful not to attract the attention of the Kempetai, the Japanese military police³. Among those volunteering, the ones who were deemed capable of surviving the hardships of life in the mountains were selected.

Once fully operational, the guerillas set about collecting intelligence about Japanese installations, troop concentrations and supplies. They made maps of these and sent these to Straughn for use by Allied intelligence. Japanese transportation facilities and communication lines were sabotaged. Firearms were secured, spies eliminated and Japanese soldiers ambushed.

By April of the following year, Cabarrubia was given the order to consolidate all FAIT units in western Batangas. The following month, these consolidated units came to be known as the 6^th Regiment of the FAIT for the entire province. By June, in recognition of Cabarrubias’ service record, he was made Commanding Officer of the entire regiment.

In December of 1943, the regiment started collaborating with Major L. H. Phillips from the General Headquarters of Douglas MacArthur’s Southwest Pacific Area (SWPA) Command, and another guerilla group operating off Calatagan led by Emilio Macabuag.

The end result of this collaboration was the setting up of radio stations in Calatagan and Balayan through which valuable information could be sent back to GHQ⁴. Many Japanese ships were sunk by American submarines due to information sent by the guerillas through these radio stations.

Regrettably, by March of 1944, the Japanese raided guerilla headquarters in Mindoro and captured an American operative by the name of Harold Guentner. Presumably with information extracted from the operative, the Japanese arrested Cabarrubia, Bahia, Deguito and Calingasan – among the original organizers of the guerilla movement – along with one Captain Demetrio Hernandez.

Bahia, Deguito and Hernandez were all executed. Cabarrubia was subsequently released because nobody would identify him as being a guerilla. The same happened to Calingasan, presumably for the same reason.

Despite being closely watched by the Japanese, Cabarrubia was quick to reorganize the resistance despite the loss of the executed battalion commanders. By June, the reorganized and reactivated guerilla groups came to be known as the Cabarrubia Guerilla Unit named after its commander.

Three months later and the group was again renamed the Rainbow Regiment, Malakas Division of the AUSA. By this time, the group was a 300-strong organization that started taking orders from the American intelligence operative Lt. Commander George F. Rowe, who had taken over from the slain Phillips.

Apart from providing vital intelligence to Allied headquarters that was crucial to planning for the impending invasion of Luzon by Allied forces, the Rainbow Regiment was active in Western Batangas protecting civilians from Japanese atrocities as well as from roaming bandits. Its guerillas also continued to engage Japanese forces to keep them distracted prior to the invasion.

On the last day of January in 1945, when the 11^th Airborne Division of the United States’ 8th Army landed on the shores of Nasugbu virtually unopposed, Cabarrubia presented his guerillas to Major Jay D. Vanderpool, who in recognition of the regiment’s vital contributions to the cause ensured that it was formally inducted into the United States Army.