Barack Obama had his first “3am moment” (test of presidential mettle) on Sunday when North Korea launched a long-range missile test. In fact, it was 4.30am when aides woke Mr Obama in his Prague hotel suite to break the news and then promptly released a statement condemning the launch.

Other than the interruption to Mr Obama’s first full night’s sleep since he embarked on his frenetic overseas tour last Tuesday, the US president cannot have been unhappy about the timing. Indeed, were it not totally implausible, bystanders could be forgiven for thinking that Kim Jong-Il had graciously scheduled the launch to coincide with Mr Obama’s big speech on nuclear non-proliferation.