2/ The surrender of the rest of Donetsk Oblast as the prerequisite of a ceasefire with no commitment to a final peace settlement ending the war would position Russian forces extremely well to renew their attacks on much more favorable terms, having avoided a long and bloody struggle for the ground. Conceding such a demand would force Ukraine to abandon its "fortress belt," the main fortified defensive line in Donetsk Oblast since 2014 — with no guarantee that fighting will not resume.