Conflict between countries will dominate next 20 years, says former top UK government official

Simon Case urges ministers to develop new means of launching UK's nuclear deterrent and says the west needs to get our skates on and be ready'

The next 20 years will be dominated by conflict between nations, the former head of the civil service has said.

Simon Case, who stood down as cabinet secretary in December, made the warning in his first major interview since leaving the job.