"Dear Mr. Prime Minister:
"I thank you for your letter of May 27 concerning American visits to Israel's nuclear facility at Dimona. I know your words reflect your most intense personal consideration of a problem that is not easy for you or for your Government, as it is not for mine.
"I welcome your strong reaffirmation that the Dimona will be devoted exclusively to peaceful purposes. I also welcome your reaffirmation of Israel's willingness to permit periodic visits to Dimona.
"Because of the crucial importance of this problem, however, I am sure you will agree that such visits should be of a nature and on a schedule which will more nearly be in accord with international standards, thereby resolving all doubts as to the peaceful intent of the Dimona project.
"Therefore, I asked our scientists to review the alternative schedules of visits we and you have proposed. If Israel's purposes are to be clear to the world beyond reasonable doubt, I believe that the schedule which would best serve our common purposes would be a visit early this summer, another visit in June 1964, and thereafter at intervals of six months. I am sure that such a schedule should not cause you any more difficulty than that which you have proposed. It would be essential, and I take it that your letter is in accord with this, that our scientists have access to all areas of the Dimona site and to any related part of the complex, such as fuel fabrication facilities or plutonium separation plant, and that sufficient time be allotted for a thorough examination.
"Knowing that you fully appreciate the truly vital significance of this matter to the future well-being of Israel, to the United States, and internationally, I am sure our carefully considered request will again have your most sympathetic attention.
"John F. Kennedy"
In conveying foregoing, you should stress that exhaustive examination by the most competent USG authorities has established scheduling embodied in President's letter as minimum to achieve a purpose we see as vital to Israel and to our mutual interests. Scientific reasons for this are that (a) only a visit before criticality can fully establish features of a reactor--this is reason for requested early summer visit which we hope could be this month or next at latest; (b) it is widely known and accepted by knowledgeable international scientific community that, if intended for ultimate production of weapons grade plutonium, a reactor of this size would be operated to burn a single fuel load approximately every six months, whereas for peaceful purposes optimum burn-up time would be about two years--this is what makes it essential that after mid-1964 visits be scheduled semi-annually.