It requires very little inside knowledge or expertise to realize that the world situation is not what it was a little while ago.
In the wake of the 1962 Cuba missile crisis and the nuclear test ban treaty, the war that really could end war (along with almost everything else) seems fairly improbable. With the removal of that imminent threat, old alliances have fallen apart, and new, relatively minor crises have popped out like the measles.
Just how the U.S. should adapt its foreign policies to meet the changed situation has not yet become the subject of a Great Debate. But...