Question: What does the US believe caused this country where Siddhi Savetsila was born in to help Japan?

Knowledge 1: Siddhi Savetsila
Siddhi Savetsila was born in Bangkok. He comes from an aristocratic background. His father was a high-ranking official in the royal government. His paternal grandfather was Henry Alabaster who was the British consul in Siam during the reign of King Rama IV (Mongkut) and then served as an advisor to King Rama V (Chulalongkorn). His mother was an offspring of the influential Bunnag family, the daughter of Thet Bunnag (later Chao Phraya Suraphan Phisut), making him a direct descendant of Somdet Chao Phraya Borom Maha Prayurawongse. [SEP] Knowledge 2: Pacific War
The official policy of the U.S. Government is that Thailand was not an ally of the Axis, and that the United States was not at war with Thailand. The policy of the U.S. Government ever since 1945 has been to treat Thailand not as a former enemy, but rather as a country which had been forced into certain actions by Japanese blackmail, before being occupied by Japanese troops. Thailand has been treated by the United States in the same way as such other Axis-occupied countries as Belgium, Czechoslovakia, Denmark, Greece, Norway, Poland, and the Netherlands. [SEP] Knowledge 3: Bang Bon District
Bang Bon (Thai: บางบอน, pronounced [bāːŋ bɔ̄ːn]) is one of the 50 districts (khet) of Bangkok, Thailand. Its neighbours, clockwise from north, are Bang Khae, Phasi Charoen, Chom Thong, and Bang Khun Thian districts of Bangkok, Mueang Samut Sakhon District and Krathum Baen District of Samut Sakhon Province, and Nong Khaem District of Bangkok.
Knowledge 1: Siddhi Savetsila
Siddhi Savetsila was born in Bangkok. He comes from an aristocratic background. His father was a high-ranking official in the royal government. His paternal grandfather was Henry Alabaster who was the British consul in Siam during the reign of King Rama IV (Mongkut) and then served as an advisor to King Rama V (Chulalongkorn). His mother was an offspring of the influential Bunnag family, the daughter of Thet Bunnag (later Chao Phraya Suraphan Phisut), making him a direct descendant of Somdet Chao Phraya Borom Maha Prayurawongse. [SEP] Knowledge 2: Pacific War
The official policy of the U.S. Government is that Thailand was not an ally of the Axis, and that the United States was not at war with Thailand. The policy of the U.S. Government ever since 1945 has been to treat Thailand not as a former enemy, but rather as a country which had been forced into certain actions by Japanese blackmail, before being occupied by Japanese troops. Thailand has been treated by the United States in the same way as such other Axis-occupied countries as Belgium, Czechoslovakia, Denmark, Greece, Norway, Poland, and the Netherlands. [SEP] Knowledge 3: Military history of the United States during World War II
The military history of the United States in World War II covers the war against Germany, Italy, Japan and starting with the 7 December 1941 attack on Pearl Harbor. During the first two years of World War II, the United States had maintained formal neutrality as made officially in the Quarantine Speech delivered by U.S. President Franklin D. Roosevelt in 1937, while supplying Britain, the Soviet Union, and China with war material through the Lend - Lease Act which was signed into law on 11 March 1941, as well as deploying the U.S. military to replace the British invasion forces in Iceland. In the Pacific Theater, there was unofficial early U.S. combat activity such as the Flying Tigers. The U.S. economic sanctions on Japan, as part of the effort to deter Japanese military aggression in Asia and the Pacific, was a major cause of the Japanese attack on Pearl Harbor.
Knowledge 1: Siddhi Savetsila
Siddhi Savetsila was born in Bangkok. He comes from an aristocratic background. His father was a high-ranking official in the royal government. His paternal grandfather was Henry Alabaster who was the British consul in Siam during the reign of King Rama IV (Mongkut) and then served as an advisor to King Rama V (Chulalongkorn). His mother was an offspring of the influential Bunnag family, the daughter of Thet Bunnag (later Chao Phraya Suraphan Phisut), making him a direct descendant of Somdet Chao Phraya Borom Maha Prayurawongse. [SEP] Knowledge 2: Bang Bon District
Bang Bon (Thai: บางบอน, pronounced [bāːŋ bɔ̄ːn]) is one of the 50 districts (khet) of Bangkok, Thailand. Its neighbours, clockwise from north, are Bang Khae, Phasi Charoen, Chom Thong, and Bang Khun Thian districts of Bangkok, Mueang Samut Sakhon District and Krathum Baen District of Samut Sakhon Province, and Nong Khaem District of Bangkok. [SEP] Knowledge 3: 51st state
In Article 3 of the Treaty of San Francisco between the Allied Powers and Japan, which came into force in April 1952, the U.S. put the outlying islands of the Ryukyus, including the island of Okinawa—home to over 1 million Okinawans related to the Japanese—and the Bonin Islands, the Volcano Islands, and Iwo Jima into U.S. trusteeship. All these trusteeships were slowly returned to Japanese rule. Okinawa was returned on May 15, 1972, but the U.S. stations troops in the island's bases as a defense for Japan.

Answer: blackmail