▁on ▁ 9 ▁February , ▁c eded ▁the ▁province ▁of ▁Che ł m ▁— ▁which ▁had ▁been ▁part ▁of ▁Congress ▁Poland ▁until ▁ 1 9 1 3 ▁— ▁to ▁the ▁new ▁state ▁of ▁Ukraine , ▁many ▁in ▁Poland ▁regarded ▁this ▁as ▁a ▁" F our th ▁partition ▁of ▁Poland ", ▁prompt ing ▁a ▁" polit ical ▁general ▁strike " ▁in ▁Wars aw ▁on ▁ 1 4 ▁February ▁and ▁the ▁res ignation ▁of ▁the ▁Jan ▁K uch arz ew ski ▁administration ▁later ▁that ▁month . ▁Part s ▁of ▁the ▁Polish ▁auxili ary ▁corps ▁under ▁Jó zef ▁Hall er ▁protest ed ▁by ▁breaking ▁through ▁the ▁Aust ro - Russ ian ▁front ▁line ▁to ▁Ukraine , ▁where ▁they ▁un ited ▁with ▁Polish ▁det ach ments ▁which ▁had ▁left ▁the ▁Ts ar ist ▁army . ▁After ▁a ▁fier ce ▁battle ▁with ▁the ▁German ▁army ▁at ▁K ani ów ▁in ▁May , ▁the ▁rem n ants ▁were ▁intern ed , ▁though ▁Hall er ▁managed ▁to ▁escape ▁to ▁Moscow . ▁ ▁Western ▁ ▁However , ▁Poland ' s ▁un spec ified ▁borders ▁were ▁threatened ▁in ▁the ▁West ▁as ▁well : ▁Late ▁in ▁ 1 9 1 7 , ▁the ▁German ▁supre me ▁command ▁had ▁proposed ▁an nex ing ▁a ▁" border ▁strip " ▁to ▁Germany , ▁a ▁policy ▁earlier ▁suggested ▁by ▁a ▁letter ▁to ▁the ▁German ▁government ▁by ▁members ▁of ▁Poland ' s ▁German ▁minor ity , ▁settled ▁around ▁Ł ód ź . ▁Such ▁plans ▁were ▁agreed ▁to ▁in ▁principle ▁by ▁the ▁German ▁government ▁in ▁March ▁ 1 9