Concerning Revelation 9:4

And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads.

Richard Nixon and Henry Kissinger took office on January 20, 1969.

The first cases of dioxin induced birth defects occurred in Vietnam in 1970.

It would have been easy to spray pure dioxin and say that the defoliation agent (orange) was contaminated.

And as my post on chapter 9 of the Revelation proves without a doubt, that is precisely what John is saying.