Appointed as Director prior to the August 1960 coup by Kong Le, Siho gathered and trained two special battalions of paramilitary police during the latter part of 1960.
When his patron, General Phoumi Nosavan, seized power in December 1960, Siho's new battalions helped carry the day at the Battle of Vientiane.
Nevertheless, the Royal Lao Army would attack and dismantle the Directorate of Coordination on 3 February 1965, driving Siho into exile in Thailand.
[4] In September 1953, Siho joined the French-led Lao National Army (French: Armée Nationale Laotiénne - ANL) as a member of its first reserve officer training class.
[9] Captain Kong Le's coup later that year in August of that year seems not to have curtailed Siho's power; he raised two special counterinsurgency battalions within the Royal Lao Police (French: Police Royale Laotiénne - PRL), trained to military standards,[7] Through Siho's influence, they were the first unit in the PRL and Royal Lao Armed Forces (French: Forces Armées du Royaume - FAR) to be completely armed with the U.S. automatic M-2 carbine.
On 17 November 1960, while acting as Phoumi's intelligence officer, he contacted a U.S. Special Forces unit, Team Ipsen.
Siho and his special battalions were loaded onto MRL landing crafts in Savannakhet on 21 November to join the latest coup.
[11] When Phoumi's forces finally reached the Laotian capital at Vientiane, Siho and his policemen led the attack.
On the final day of the Battle of Vientiane, December 16, Siho's police unit successfully captured the Royal Lao Air Force (RLAF) military runway at Wattay Airfield.
[17] This action was ended in December when Siho's demand for tactical control of the operation through the communications network was refused.
[20] On 18 April 1964 there was a tripartite meeting on the Plain of Jars, as Souvanna Phouma met with his brother Souphanouvong to thrash out a coalition agreement.
They arrested Souvanna Phouma and 15 leading officials of several opposed factions such as the Royal Lao Army, Forces Armées Neutralistes, and the French Embassy.
Communist forces promptly moved into the defensive positions strung along the north edge of the Plain of Jars that had been abandoned by GM 17.
He confronted Siho and the mutinous Lao officers and informed them that the United States supported Souvanna Phouma; that was the end of the coup.
[23][25] In December 1964, Siho seized the socially prominent editor of a Vientiane newspaper, sparking widespread outrage from the military.
However, despite their non-participation in any coup activities, a company of BS 33 guarding the Frontier Police headquarters at Muong Phene was overrun by RLA tanks and dispersed on 3 February 1965.