Blood and treasure or fantasy: What is the UK-U.S. 'special relationship'?

A student wears British and American flags in Los Angeles, California, U.S., May 15, 2018. REUTERS/Mike Blake

LONDON (Reuters) - Britain's so-called 'special relationship' with the United States was one of the most enduring alliances of the 20th Century, though Brexit and the election of U.S. President Donald Trump have raised questions about its future.

What is the special relationship and how do the United States and Britain compare on key measures?