The warning from Ukraine to Belarus is blunt.
“Your leadership is planning to drag the Belarusian people into a dirty war, to stain them with blood and death,” the video released by the Ukrainian military declares.
“If the Belarusian army supports Russian aggression, we will respond… with our entire arsenal of weapons.”
The warning comes as Russia is sending thousands of troops back to Belarus, prompting fears the two countries could be planning a joint incursion across Ukraine’s northern border.
That would be politically risky for Belarusian leader Alexander Lukashenko – and Russian forces are already struggling to hold their current lines around the southern city of Kherson and in Donbas in the east.
But the prospect alone is a distraction and a concern for Kyiv as Minsk comes under pressure from Moscow to step-up its support.
“I think Putin really wants Belarusians to enter Ukraine so that Lukashenko… is bloodied, too, and will have to go to the end with him,” is how Valery Sakhashchyk, the former commander of an elite paratrooper unit, reads the recent moves.
Now in Warsaw, he is effectively the defence minister in a transitional cabinet of the Belarusian opposition-in-exile.
The fuss was sparked when, after meeting Russian President Vladimir Putin earlier this month, Alexander Lukashenko claimed that Belarus’s neighbours were planning to attack.
He then announced that Minsk and Moscow were forming a joint “regional group” of forces for protection.
Mr Sakhashchyk puts the risk of the two countries opening a northern front in Ukraine as one in three, currently.
But he describes the long-time leader of Belarus as a “wily” operator.
“Lukashenko will do everything possible not to send his troops to fight, to limit them to a supporting role, but there is certainly a threat.”
Belarus is already heavily involved in the Ukraine war.
In February, Russian tanks crossed its southern border towards Kyiv and Russia regularly launches missiles from Belarusian territory. The EU is currently preparing another punishment package of sanctions in response.
But if President Putin is pushing him for more, Mr Lukashenko has limited room for manoeuvre.
The authoritarian leader has been dependent on Russia since 2020, when support from Moscow helped him survive an unprecedented wave of protests.
Meanwhile, the mass imprisonment and torture of protestors hammered one nail in the coffin of relations with the West. Belarus aiding Russia’s invasion was another.
Mr Lukashenko says up to 9,000 Russian soldiers will come to Belarus for the new group. But sending Belarusians alongside them into Ukraine would be a deeply unpopular move.
Several hundred Belarusians are already fighting in Ukraine – against Russia. Known as the Kalinovsky regiment, they openly say they joined the war to defeat Vladimir Putin so that Belarus, too, can be free.
There is also resistance inside Belarus where partisans sabotaged railway lines at the start of the invasion to hinder the movement of Russian troops. Last week, another of the group was sentenced to 11 years in prison.
“I get lads writing and saying we don’t want to fight [against Ukraine],” Pavel Kukhta, of the Kalinovsky regiment, told me at their recruitment base in Warsaw.
“My sources in the Belarussian army say 90% won’t fight. They say the training’s bad and kit and morale are even worse than the Russian army.”
Just a bluff?
There have been rumours of a secret mobilisation in Belarus, but nothing substantiated.
Meanwhile, Russian forces are already on the move.
Ukrainian intelligence reports that 3,200 Russian soldiers have been sent to Belarus to date. More are expected, but it is a trickle not a rush and so far they are heading for northern and central parts of the country, rather than the Ukraine border.
“They don’t bring any heavy equipment, there was just one train loaded with pontoon bridges but no tanks or personnel carriers,” Belarusian journalist Tadeusz Giczan also points out.
He believes the Russians are actually being sent for training, with their own facilities overstretched since President Putin announced a partial mobilisation.
“They need more capacity. Belarus offered to provide it and perhaps kill two birds with one stone: threaten Ukraine with a potential new offensive from the north. It’s just a bluff.”
The Russian men shown in Belarusian defence ministry videos appear to be “mobiki” – recently mobilised reservists, not regular troops. Some have non-military items of kit or clothing.
Valery Sakhashchyk agrees they could be training.
“They need a lot of instructors and Russia has a problem with that as they’ve lost a lot of men.”
The mobiki could then be deployed to the border, but that would be detected.
For now, a Belarusian monitoring group sees equipment heading out of the country instead.
The Hajun project says more than 90 tanks have been transported to Russia in recent weeks, likely urgently needed replacements for Donbas.
It sees no major new build-up of equipment or missiles at the base used by Russia near the Ukraine border.
What if a joint force went in?
Some argue that committing Belarusian troops to Ukraine would be pointless, militarily.
“They’re not skilled, not equipped and not motivated. They won’t pose a threat,” opposition politician Franak Viacorka has tweeted.
But Valery Sakhashchyk cautions they should not be discounted.
The Ukrainian military suggests a new, joint force could try to cut off its supply routes from the West, giving Russian troops a better chance on the battlefield.
“If they mobilised to military level it would be a serious attack force which would be unpleasant for Ukraine. They would have to move significant forces to the north, they would sustain significant losses,” Mr Sakhashchyk says, though he thinks Belarusian morale would be low.
“They would make things harder, make it slower to reach victory – but Ukraine will win.”
The video produced by Ukraine’s military fast-cuts images of tanks and missiles with Mr Lukashenko and President Putin and calls on Belarusians not to die for the personal ambitions of two dictators.
But Alexander Lukashenko’s desire for power may be just what prevents their deployment.
“It would likely be a big catastrophe for the Belarusian army and for Lukashenko himself. So he’ll be trying to talk his way out of this and his negotiating position is still quite strong,” says journalist Tadeusz Giczan.
“He can still convince Putin that the Belarusian army would not add much capacity… in Ukraine, but [the deployment] could backfire pretty badly and destabilise Russia’s only proper ally.”
In his battle to stop Ukraine escaping Russia’s grasp for good, Vladimir Putin will not want to risk losing Belarus, too.