considering this song was first performed in 1961, i highly doubt the vietnam reference. Also, this song was originally a 1959 poem by Leonard Lipton, who then gave Peter Yarrow his lyrics who proceeded to make it into a song. I also highly doubt it is a marijuana reference because Leonard lipton based his poem on the Ogden Nash poem, "The Tale of the Custard dragon" (http://www.eecs.harvard.edu/~keith/poems/Custard.html) which is cleary not a marijuana reference.
considering this song was first performed in 1961, i highly doubt the vietnam reference. Also, this song was originally a 1959 poem by Leonard Lipton, who then gave Peter Yarrow his lyrics who proceeded to make it into a song. I also highly doubt it is a marijuana reference because Leonard lipton based his poem on the Ogden Nash poem, "The Tale of the Custard dragon" (http://www.eecs.harvard.edu/~keith/poems/Custard.html) which is cleary not a marijuana reference.