What is the "upon us"?
Does this word mean we are facing a new Cold War?
the context:
Now, within Russia, state-controlled media may describe these events as an example of a resurgent Russia -- a view shared, by the way, by a number of U.S. politicians and commentators who have always been deeply skeptical of Russia, and seem to be convinced a new Cold War is, in fact, upon us.

Question

What is the "upon us"?
Does this word mean we are facing a new Cold War? 
the context:
Now, within Russia, state-controlled media may describe these events as an example of a resurgent Russia -- a view shared, by the way, by a number of U.S. politicians and commentators who have always been deeply skeptical of Russia, and seem to be convinced a new Cold War is, in fact, upon us.

Answer

Yes, indeed. "A new Cold War is, in fact, upon us" = it is going to happen very soon

Answer

war is upon us = war has come up on us = has arrived = has approached us and is now "on us".