As long as they are used defensively, weapons are needed. And having the latest and greatest weapons really helps. We can see this play out in Ukraine clear as day. If Ukraine had more weapons in the beginning, Russia hadn't invaded. If they had anyways, Ukraine would've been able to rebuff them with more force. Whenever the West does send weapons to Ukraine, they have an immediate and devastating effect on Russian troops. But because we are sending so little, the war bogs down into a WW1-style slugfest. Also, the ammunition given by the West allows Ukraine to do targetted strikes mostly. Russiaon the other hand is just sending wave attacks, accepting massive civilian casulties.