In August of 1991, the Soviet Union was on the verge of collapse. In order to stabilize the situation, a group of hardliners attempted to oust Mikhail Gorbachev is what is now known as the August Coup. The Coup failed and led to the final blow to the Soviet Union.
In this timeline, Things happen differently which allow the Coup's success. In 2015, The world struggles to balance the Still existing Soviet Union and the now expanded Western World. This is what has come as a result.