Vladimir Putin is flexing his might. Joseph Biden is wagging his finger and using harsh condemning language. Today explosions were heard on the borders of Ukraine; obviously Putin is not dissuaded in the least by usa's empty rhetoric. Will Russia now feel emboldened to continue attacking Europe? Will China ally itself with Russia and just start the war ultimately that we all lose? Am I just being paranoid? 

usa troops are being stationed near Ukraine; will that lead to a confrontation usa vs. Russia?

Nuclear warheads are piled high in all of these countries as well as many others. 

The question is; are any of these leaders crazy enough to use them?