British intelligence sources have confirmed that Russian military units are amassing in eastern Ukraine, preparing for a large-scale offensive in the Donbas region. The warning, issued late Wednesday, cautions that an assault could begin within days, threatening to redraw the front lines and escalate the conflict to new heights of violence.
Sources close to the Ministry of Defence described satellite imagery showing columns of tanks, artillery batteries, and troop convoys moving towards the front near the cities of Kramatorsk and Sloviansk. The build-up mirrors patterns observed prior to previous Russian offensives, including the capture of Mariupol earlier this year.
“This is not a feint. They are moving armour, logistics, and infantry in numbers consistent with a major push,” one intelligence official told me, speaking on condition of anonymity due to the sensitivity of the matter. “The target is likely the remaining Ukrainian-held parts of the Donetsk and Luhansk oblasts.”
The assessment has been shared with NATO allies, who have privately echoed the alarm. A senior Western diplomat described the situation as “the most dangerous moment in months,” warning that a renewed Russian offensive could overwhelm Ukrainian defences if Western aid does not arrive swiftly.
Ukraine’s General Staff has admitted that Russian forces are “concentrating efforts” in the east, but maintains that defensive lines are holding. President Zelenskyy, in a nightly address, called on partners to accelerate deliveries of heavy weapons, saying: “We need every day. Not next month. Now.”
The Donbas has been a focal point of the war since 2014, but the scale of the current build-up surpasses anything seen in recent memory. Procurement documents obtained by this newspaper show Russian defence firms have ramped up production of artillery shells and drone parts, with supply lines stretching from factories in the Urals to railheads in Rostov.
Meanwhile, reports from the front indicate an increase in probing attacks and electronic warfare jamming, classic pre-offensive tactics. Local officials in the Donetsk region have begun emergency evacuations from towns within range of Russian artillery.
The timing of the assault, if it comes, may be calculated to exploit delays in Western military aid. A $60 billion package for Ukraine remains stuck in the US Congress, and European stockpiles have been depleted. Analysts warn that Ukraine’s ammunition shortages are becoming critical.
“The Russians see a window,” a former CIA station chief told me. “They know that if they hit hard now, before the West resupplies, they could break through.”
A Russian offensive in the Donbas would likely aim to encircle or cut off Ukrainian forces in the region, potentially leading to a large-scale siege or collapse of defensive lines. The human cost would be staggering. Civilian casualties in previous battles have already numbered in the thousands.
As the world watches, the countdown has begun. Every day of delay, every political squabble in Washington or Brussels, has a price measured in blood on the Ukrainian steppe.