The concern from some NATO members is an escalation to a wider conflict that includes NATO, especially if NATO weaponry is used inside Russia. Even for use inside Ukraine there has been a significant foot dragging to supply weapons, like moderns tanks and long-range missiles. So far only air planes from the Soviet Union era has been given to Ukraine, and a number of them is not even in the best (i.e. usable) condition.\n\nSo here we are, but do recall that more and more advanced weaponry has been given to Ukraine over time, after some procrastination.\n\n\nI'll look for the name, but I watched a video with the former head of a US military branch who said that the goal for Ukraine isn't to win, it's to prevent them losing. He said that the West is afraid of Putin's threats to use nukes and they're doing only as much as it takes to prevent that.