Stupid. ALL defensive lines can be overcome, ie Marginot Lines.
The actual biggest aid to Russian reinvasion of Kharkiv is the months long stoppage of US aid, causing artillery shortage, and the stupid US insistence that its weapons cannot be used on Russian soil which stopped Ukraine from striking the attacking Russian army with Himars or Atacms.
U.S. officials have repeatedly said that they do not support or encourage Kyiv's strikes with American weapons at Russian territory, while Ukrainian officials are reportedly trying to convince Washington to lift this ban.
If you go to the artillery shell store and there ain't no artillery shells, that's where an artillery shortage comes from.
BTW - we all know that the US was sliding arms and ammo to the Ukraine under the table before the DC establishment passed the bill to make the under-the-table stuff legal.
So, that was all "paid forward" beforehand.
Nice try with your propaganda, though! 
The whole reason this operation is happening is because Ukraine kept shelling civilians in Belgorod, so your response is that Ukrainians should be supported in continuing their attacks on Russia? Wow.