I won't get into the more recent things; I'll just set out some historic facts concerning your first items.

Germany did not physically attack the U.S., true, but did declare war on the U.S. as soon as Pearl Harbor occured, before the U.S. acted. Germany and Japan were in an alliance such that a Japanese attack constituted one by Germany.

If any one President could be said to have started the Viet Nam conflict, it would be Eisenhower. He took it over from the French and American advisers were in the country from then on. Kennedy continued his policy. Similarly, Johnson can hardly be accused of creating a quagmire there; it had been a quagmire for the French and was for the U.S. from the very beginning. A succession of Presidents, Democrat and Republican, continued to back the war there because they couldn't find an 'honorable' way to get out. Of course, there was no 'honorable' way out, as Nixon demonstrated.

I suggest you read 'The March of Folly' by Barbara Tuchman, which describes the Viet Nam experience along with other great follies, including the loss of the American colonies by the British and the Reformation, caused by the hubris of a succession of Popes. Although some have suggested that the American adventure in Iraq falls in this tradition, by Tuchman's definition it does not, yet. For it to be a Folly on her scale, a succession of U.S. administrations would have to stagger on this course.