Arriving at the secret location a short drive from the Russian border I’m advised to avoid huddling together in a group.
You never know who or what might be watching and the military command post we are visiting is a high-value target for Vladimir Putin’s forces in eastern Ukraine.
We form a well spaced line under a roof cover so that, from the air at least, it would be more difficult to see how many people are there.
It’s easy to make light of such precautions, but we are in a warzone and sloppiness, especially by reckless journalists, gets people killed.
Details such about locations and wide angle photographs of the landscape might seem inconsequential in newsrooms thousands of miles from the front line, here in Eastern Ukraine letting the wrong thing slip to the enemy is a matter of life and death.
This fact was made abundantly clear when I’d attempted to speak to a reluctant British soldier fighting alongside Ukrainians earlier in the day.
“Could we speak if he covered his face?” I asked, hoping to find a compromise.
“No,” his officer replied, ”He says there was a time when someone spoke to the press and his whole unit was killed.”
Just to check the officer calls him over to see if a direct assurance might change his mind.
The soldier dutifully walked towards the two of us but with his head contorted in the opposite direction. He didn’t want me to catch even a glimpse of his face.
I understand his concerns. A colleague told me of a recent example when a journalist was granted exceptional access to a unit on the Ukrainian frontlines and went on to name the exact location in his article.
When he’d hit publish the lives of the men he’d written about were in immediate danger. Forced to rapidly move a complex command post to a new location, their unit and who knows how many other troops were placed at a strategic disadvantage.
The Kharkiv region is a place of vast farmland where acres of potato fields make the horizon look even wider than normal. You can only gaze into the endless sky and wonder how or where the next attack might come. The threat is omnipresent.
I remind myself that fears about an enemy attacking civilian areas from the air are nothing new. In the First World War great German airships floated ominously across the Channel to attack Britain.
But those huge balloons, or the Luftwaffe bombers which followed, were either large or noisy. The terrifying thing about drone warfare is how small and imperceptible it can be
Whizzing past in seconds these devices can capture a unit’s position and pass the information to a Russian airfield for a massive rocket attack.
Sometimes it doesn’t even take a drone because, thanks to our mobile phones, nearly all of us walk around voluntarily communicating our geo-location to some random satellite. It’s information which could, should it fall into the wrong hands, present a massive security threat.
In Ukraine, evidence that such tools cause tragedy is not hard to find.
The previous day, I was told by Kharkiv’s police chief that a Russian rocket attack on a funeral reception, which resulted in the death of around 40 civilians, came about after an informant dropped a message to the enemy on his mobile phone.
There are few places in Ukraine that feel safe, but in the east danger levels are considerably higher. Merely entering the region prompts your iPhone to issue an ear-splitting warning sound advising you to turn around.
The Russian city of Belograd is a short distance from Kharkiv and it’s very easy for Putin’s forces to launch rocket and drone strikes across the border.
Reminders of the consequences of those attacks are everywhere. There are almost no streets without flattened buildings or holes from explosions.
Many of the walls also bear the pock-marks of gunfire from the Battle of Kharkiv-where Ukrainian forces pushed back the Russians after they had seized the city. It feels close, it could happen again.
Despite the strict 11pm curfew or the soldiers with guns constantly checking your car, life in the Kharkiv region can still be found in abundance.
As air raid sirens whine through the fresh spring air boys do wheelies on BMX bikes and girls swaying their arms in unison for a TikTok dance routine.
They are some of the millions in Ukraine’s front lines and occupied territories who live in the terrifying uncertainty. A kamikaze drone could crash into their apartment block at 2am or the glass-fronted restaurant beside their workplace could be blown to pieces by a rocket attack tomorrow, but stopping what they do today, well, that only lets the Russians win.