Conspiracy theory without any substantiated proof. The claims of US implications are based on an article published by N-TV on 8 March 2019. The article titled "Three theories on the fate of MH370" gives three versions of the Malaysia Airlines Flight MH370 tragedy, a pilot's suicide, hijacking and US-Thailand military exercises in the South Chinese Sea. Regarding the third theory, the article says: "The third theory is connected with a missile launch, accidental or deliberate. It assumes that the aircraft was shot down in a joint military exercise by Thailand and US in the South China Sea. This is similar to the case that took place a few months later with Malaysia Airlines flight MH17 in Ukraine".
The hypothesis that the Flight MH370 jet was shot down during a U.S.-Thai exercise was voiced in 2014 in Nigel Cawthornes's book Flight MH370: The Mystery, among many unofficial disappearance theories of the Malaysia Airlines Flight 370. However the book received considerable criticism and was not taken seriously by investigation teams, i.e. the theory can be considered a conspiracy.
The Dutch-led Joint Investigation Team has concluded that flight MH17 was shot down on 17 July 2014 by a missile of the 9M38 series, launched by a BUK-TELAR, from farmland in the vicinity of Pervomaiskiy. At that time, the area was controlled by pro-Russian fighters. The BUK-TELAR was brought in from the territory of the Russian Federation and subsequently, after having shot down flight MH-17, was taken back to the Russian Federation.