I was referring to the 1958 moratorium I'd be surprised if they could simulate weapons with the computers of the time. Here [1] is the clip from Teller's interview.

In another clips he says that he believes it was inevitable that the Soviets would come up with an H-bomb on their own.

[1] https://www.youtube.com/watch?v=zx1JTLrhbnI&list=PLVV0r6CmEs...