An inter-Korean air-traffic hotline still exists.

BBC: US B-2 stealth bombers in South Korea drill

For the past 60 years, air travel has been governed by inter-governmental deals which dictate which airlines can fly where, how many seats they can offer and even, in many cases, what fares they can charge.

ECONOMIST: Now is the time to set the world's airlines free

Should that match in Italy go ahead if European air travel resumes following the volcanic ash fallout from Iceland, Inter boss Jose Mourinho will have eagerly noted Espanyol's success in nullifying Barcelona's star-studded line-up.

CNN: STORY HIGHLIGHTS