Sorry, I went back for further reading. Thailand declared war on Great Britain and the United States on January 25, 1942. The British responded by declaring war on Thailand; the U.S. government ignored Thailand’s declaration of war. The war declaration on the USA was delivered through the Swiss government, representing US interests in Thailand. It was Seni Pramot, Thailand's Ambassador to the US who reportedly did not deliver the declaration of war in Washington. That may have been a face saving story as Pridi pointed out in raising the question as to way Seni would have been directed to deliver the declaration already transmitted through the Swiss previously.