3 ms·

The Soviets did it too: https://en.wikipedia.org/wiki/Joe_4 https://en.wikipedia.org/wiki/Joe_4

• arethuza 11y ago
  I think you could argue that the Joe 4 design was an attempt to design a H-bomb using a different approach that turned out to be a dead end - the US was aware of this design but never tested it. Whereas the UK just plain lied and continues to be evasive about the matter to this day - probably because the exercise was mostly aimed at the US.
  • m-i-l 11y ago
    The Grapple X on 8 November 1957 (a few months after the Grapple 1 on 15 May 1957) was a successful thermonuclear device[0], so it was only a short term bluff. Bear in mind that this was in the context of the British feeling betrayed by the Americans on nuclear research - from https://en.wikipedia.org/wiki/Atomic_Energy_Act_of_1946 https://en.wikipedia.org/wiki/Atomic_Energy_Act_of_1946 : "Implementing the McMahon Act created a substantial rift between United States and Britain. The new control of 'restricted data' prevented the United States' allies from receiving any information, despite the fact that the British and Canadian governments, before contributing technology and manpower to the Manhattan Project, had made agreements with the United States about the post-war sharing of nuclear technology. Those agreements had been formalized in the 1943 Quebec Agreement. In the case of the United Kingdom, these were developed further in the 1944 Hyde Park Agreement, which was signed by Winston Churchill and Franklin Roosevelt" [0] https://en.wikipedia.org/wiki/Operation_Grapple#Grapple_X https://en.wikipedia.org/wiki/Operation_Grapple#Grapple_X