The "Red Orchestra" and "Lucy" spy rings sent invaluable data to Stalin during WW2. Thus for the July 1943 Kursk offensive the Soviets were fully prepared. But Stalin refused to heed the July 1941 Barbarossa warning & the Soviets were caught with their pants down. WI Stalin had put his forces on full alert a week before? Although the Red Army officer cadre had been bled white in the purges, could the Russians have launched a preemptive spoiling attack to blunt Hitler's assault, or even cause it to be called off altogether? Or at least slow it down much more than in OTL? Or was Russian incompetence at that time so bad that it would not have made much difference? Even in 1943, despite being fully prepared, the Soviets still came close to losing.