250. Memorandum From Secretary of Defense McNamara to President Johnson1
SUBJECT
- Project Pop Eye
As you know, we are vitally interested in reducing infiltration into South Vietnam through the Laotian panhandle. Vehicular travel in this area is virtually halted by softening of the road surfaces during the monsoon season. Project Pop Eye is a covert and highly classified operational experiment which we plan to run within the next few weeks in the Laotian panhandle. It will determine the feasibility of increasing the rainfall during the current monsoon season and possibly extending its duration.
The objective would be to damage the trail structure by heavy rain. The materials involved are non-toxic and will not harm vegetation. The increased rainfall will be limited to a small controlled area, approximately 200 square miles. Plans have been made and will be put into operation within approximately 20 days—just prior to the end of the normal monsoon season.
Concurrence in the merits of the experiment has been received from both the JCS and the theater commanders. Technical adequacy of the experiment has been verified by Dr. Hornig who concurs that we should proceed. Approval for the conduct of the test has been received from Ambassador Sullivan under the condition that it be run covertly, and the State Department has also concurred.
I have authorized the program to proceed even though there may be some objections raised by the international scientific community—if there is a breach in security. Such possible objections have not, in the past, prevented the carrying out of military operations considered to be in the interests of our national security.
The task of inhibiting infiltration into South Vietnam is one of our most serious unsolved problems—this project might offer a partial solution, if the experiment is successful.
- Source: Johnson Library, National Security File, Country File, Indonesia, Vol. VII, 5/66–6/67. Top Secret.↩