The pandemic has restricted travel in almost every country for the last year, squeezing tourism in the name of national security from Covid infections. The reduced traffic will have had little impact in some airspaces, as pilots won't cross into regions where they could court a military response. The type and intensity of danger pilots could face depends on the country, and maps show where they should and shouldn't stray.

       Planes are among the smoothest modes of transport, up to 19 times safer than cars.

       But this rule applies primarily to the first world, where nations police their airspace diplomatically.

       Other countries may not follow this path and instead operate a zero-tolerance policy for stray flights.

       READ MORE: London given 'boost': Brexit Britain reaffirms 'global hub' status

       These nations are often engaged in national conflict and target planes flying above as aggressors.

       Some of these nations may also border others with more diplomatic policies but warrant concern by association.

       The Conflict Zone and Risk Database splits countries into three risk levels; moderate risk, assessed risk and caution.

       Each of these specifies active airspace warnings, a local war zone or national air incidents.

       The deceptively named "moderate" risk areas are otherwise known as no-fly zones.

       Pilots who stray into these areas could court aggressive military response.

       Parties on the ground below may have access to Surface to Air Missiles or other aircraft targeting systems.

       Leaders and organisations in each of the "moderate risk" countries advised planes against entering local airspace.

       As such, they must prioritise avoiding the following areas at all costs.

       They include:

       DON'T MISS

       Europe holidays: Ryanair boss urges UK to join EU Covid pass scheme - INSIGHT

       Boris to thrash out EU Covid travel restrictions in talks with Merkel - ANALYSIS

       Civilised world must bring rogue states to heel says FREDERICK FORSYTH - COMMENT

       Assessed risk is a term used to describe countries under airspace warnings from national or international organisations.

       In the UK, the Department for Transport handles advice for civil aviation, while other international organisations release communications of their own.

       The European Union Aviation Safety Agency (EASA) issues warnings for the bloc's 27 member states.

       Warnings applied to countries included in the assessed risk area list come into effect for specific regions and altitudes.

       Many have emerged in areas with a secure national government undergoing social upheaval.

       Assessed risk areas include:

       The Conflict Zone and Risk Database built its caution area list out of countries not officially recognised as risky.

       These areas, it states, do not have multiple active airspace warnings in effect.

       But they should warrant some caution or security review before people consider flying over them.

       Caution areas include a selection of countries with noted recent airspace controversies.

       These controversies came either as a result of internal disputes or threats from neighbouring countries.

       The caution list includes: