Many Oklahomans grew to disapprove of the Vietnam War because Congress never officially declared war, the US military made little progress, and __________.

Along with the lack of an official declaration of war and little military progress, the draft caused many Americans to oppose the Vietnam War. Most men over eighteen had to register for possible military service, which angered people who feared being sent to fight. The other choices describe support for containing communism or fears of a wider conflict, not the likely source of growing disapproval in this question.

AI-written and checked against the verified answer.