In 1957, a British company helped the Soviet Union win a huge Cold War victory.
According to a newly declassified CIA report, in "April 1957, a small number of mercury battery packs were shipped from a U.K. battery manufacturing company to the Soviet Union." The report offers a "consensus" that "the batteries were used as a power source for transmitters in Sputnik I and Sputnik II."
While Britain was then and remains today America's closest ally, this incident proves no ally is perfect. (Considering the U.S. leaks of British intelligence following this summer's terrorist bombing in Manchester, it is fair to say that this dynamic goes both ways.) Reflecting the awkwardness of a British company inadvertently/or deliberately supporting the Soviet Union, and that the CIA's information seems to have come from a human source, the report remains heavily redacted even today.
Still, its import is significant.
After all, the successful Sputnik 1 and Sputnik 2 missions were a huge propaganda success for the Soviet Union. Occurring under the hardline premiership of Nikita Khrushchev, one year after the failed Hungarian revolution against Soviet rule, sputnik offered a huge credibility boost to the Soviet project. With such an early conquest of space, the Soviet Union signaled its credible intent to make communism the way of the world.
In Washington, the sputnik launches were political gut punches. In turn, we must assume President Dwight Eisenhower was not terribly pleased when briefed by the CIA that a British company had been instrumental in sputnik's success. Again, history is also relevant here: This was one year following the Suez Crisis showdown between Britain and the U.S. While relations would improve in 1958, had Eisenhower not recognized the importance of alliances to U.S. national security interests, the special relationship might have imploded.
Fortunately, it did not.