As the Russians closed in on Paris, a select group of scientists made a plea to the UK. The scientists made much advancement in rocketry, ballistics, aerodynamics, artillery, small arms, and medicine. However, during the invasion of Russia, the Vichy’s were unkind to both POWs and citizens. As Russia began the march across Europe, they returned the favor in kind. Many of the scientists could see that France would lose the war, and they knew that Stalin had no reservations to execute the enemy, even one whose talents could be put to use. Indeed, Stalin had killed or sent to Siberia many of his own brilliant citizens to stifle their political thought, or to make an example of them.