Now that he has decided not to place interceptor missiles in Poland and a radar complex in the Czech republic, you can be sure that Russia will continue to flex its muscles in the region.  Giving in to Russian strongman Putin is not the way to secure peace and stability. Poland and the Czech republic broke away from Russian hegemony after the collapse of the Berlin wall, and have become strong backers of US policy. Russia seeks to bring those two back under its sphere of influence. The US decision to abandon the mutual preparedness policy is only going to embolden Putin to take more steps and press his positions more firmly.