Through the first line of russian defences. Our security correspondent Frank Gardner has been working with the bbc verify team to determine whether ukraine is making any significant process. Ukraines big Counter Offensive in the south is making progress, but how far have their troops really got and can they break through russias defences to turn the tide of this war . Lets just remind ourselves. The Dark Red Area is the area occupied by Russian Forces. The purple area is ground that the ukrainians have recaptured. The russian defences consist of two major lines, each composed of several interlocking obstacles trenches, anti tank devices, minefields, all covered by artillery. The ukrainians have had to spend most of the last three months picking their way through minefields like this one. You can see the hidden mines circled in red here. And theyre doing this on foot, sometimes at night, often underfire, hence the slow progress to date. Theyre also having to find their way through obsta