Forces News has been granted rare access into a mission onboard a NATO AWACS aircraft - known by the alliance as the "eyes in the sky".
The AWACS (Airborne Warning and Control Surveillance) aircraft, a Boeing E-3A, has helped protect NATO airspace close to Russia since it annexed Crimea in 2014.
It has also played a key role in the fight against so-called Islamic State.
The surveillance plane's distinctive radar dish makes the AWACS easily identifiable, although the aircraft is in fact a modified, 20th-Century Boeing 707, once used by commercial airlines.
Inside, however, it is a far cry from a commercial jet, being kitted out with technology capable of pinpointing any ship or aircraft more than 250 miles away.
With cases of Russian aircraft flying close to NATO airspace continuing, the AWACS remains a key cornerstone of NATO defence.
"The importance, you might argue, has changed a little bit," said Air Commodore Andrew Martin, Deputy Commander of NATO Airborne Early Warning and Control Force.
"The professionalism of the crews, maybe there's a bit more focus there but the people, the boys and girls who work here, the men and women, really, their professionalism is outstanding.
"They are always focused on their job, providing that extra capability that we do so well is just the same."
Watch: "Providing that really visible presence to the nations who need reassurance most is something that we do very very well," said Air Commodore Andrew Martin
At NATO's Geilenkirchen Air Base, three AWACS aircraft take to the sky for a routine mission.
Between them, they can scan NATO's entire European airspace, allowing a 360-degree radar picture to be shared instantly with fighter jets and other military users.
Russian airspace, meanwhile, is marked in red on cockpit monitors.
“We can see assets coming our way, probably not friendly assets coming our way, at a pretty large distance," said Lieutenant Colonel Raimond Schulz, Mission Commander, from the German Air Force.
"The advantage of our radar is that it does not stop at the border."
Concentration is a major factor for staff working on the AWACS, with crew monitoring screens for up to six hours at a time.
The aircraft themselves are designed to fly for more than ten hours and can re-fuel mid-air.
The AWACS, also referred to as the 'big eye' and the 'big brain', can lead up to 150 aircraft at a single time.
There are no British crew members, with Germans and Americans forming the majority of the multinational team.
The skills of the crew impressed prospective Royal Air Force pilot, Flying Officer George Long, who is currently attached to a NATO AWACS squadron.
"It is just awesome on a personal level and a business level, everyone gets on well the whole time," he said.
"Work gets done and that's what NATO is doing."
Britain has its own AWACS but not all NATO countries can afford the radar planes.
Geilenkirchen's fleet of fourteen Boeing E-3As is a result of 16 nations clubbing together to jointly fund the aircraft.
They are among the few NATO military resources that are not owned by individual member nations.
The alliance is now considering a long-term replacement for its ageing AWACS, but the prospect is still many years away.
The existing aircraft are being upgraded and the plan is to extend their life until 2035.