Lack of real-world testing raises doubts on U.S. missile defences

WASHINGTON (Reuters) - When simulating missile attacks from North Korea or Iran, the U.S. military says its defence system and network of radars allow it to successfully track and destroy incoming warheads.

But test conditions do not accurately mimic those of wartime and critics are sceptical the country can truly defend itself, even after spending $40 billion over 18 years of research and development.