Recently a friend took me on a tour of Yorkshire, England, including the famous Yorkshire Moors. But the most stunning part of the landscape was a huge radar installation, operated as part of a giant system deployed in the Cold War to protect the U.S. against nuclear missles:
At first, it was a bit difficult for me to understand why a radar installation in northern England would be much use to safeguard the U.S. But when you look at how the different systems overlap, it becomes quite clear: