As winter sweeps across Ukraine the ideal window for its counter-offensive is now closed, with seemingly minimal gains from five months of hard fighting.

 So what happens next? Sitrep assesses whether Ukraine has another chance for a significant fightback next year, and if so how it could do that.

Professor Michael Clarke, Ukrainian researcher Mariia Zolkina, and former infantry officer Ed Arnold discuss the military options, and we hear from Kyiv about the mood there.

And we get an insight into one of Britain’s newest military units, the National Cyber Force, from Lieutenant General Tom Copinger-Symes who oversees their defensive and offensive operations.