The new threat is the soldiers of North Korea. Can NATO troops enter Ukraine now?
Although not overtly, the soldiers of many NATO countries are participating in the war on behalf of Ukraine and receiving a lot of military equipment from them. About 1,500 North Korean fighters are already ready to fight against Ukraine on behalf of Russia. I think Russia should have that right.
I would suspect that Russia and North Korea will used Kursk as a useful training exercise to work on integration of their forces...in anticipation of a future need.
The surprisingly stupid Kursk adventure turns out to be the gift that keeps on giving for the Russian side. The idea that the invasion was a surprise to the Russians is absurd given their intel capabilities and the time took to consolidate Ziocon forces for the operation. I again, as I did within the first days after Kursk, wonder aloud if Russia didn't actively foster the incursion knowing that it would be a giant gift (albeit at some cost in 'face', civilian discomfort, and property destruction.) Maybe even the Zionazis and the Kremlin planned it together. I would not rule that out.
Kursk is, of course, 100% 'old Russia' which simplifies things legally by a fair margin, though I expect that Russia could argue that by their laws, the five regions where the populations voted to join the Russian federation are also fair game for employing forces from allied nations.