Russia's new all-out assault on east Ukraine has escalated - the Kremlin unleashing thousands more troops in what is being called the Battle of the Donbas, a campaign to seize two provinces.
Overnight, Russian forces pushed further into the beseiged country's industrial heartland - which comprises the two big regions of Luhansk and Donetsk.
Standing before them are some of Ukraine's best trained troops - already posted in the east because of the eight-year war with Russian-backed separatists.
Russia has claimed control of Kreminna, an eastern town of 18,000 people, but the governor of the Luhansk region's administration, Sergei Hadai, said Ukrainian forces were now regrouping.
Justin Crump, a former British tank commander who is now a military strategist and the CEO of intelligence consultancy Sibylline, spoke to Corin Dann.
