Has the "Cold War" of Western Nations versus Russia been restarted? If so how should US respond?

Since the fall of the Berlin Wall and breakup of the Soviet Union, most of our military engagements have been around the Mediterranean Sea or Southwest Asia. We have drawn down our forces and reduced our nuclear response capability as we have tried to use diplomacy to address world problems.
The US and many "western" nations have reduced defense spending relative to GDP while Russia has increased their spending made possible by economic growth. The past few years have shown us working with Russia at the UN on rare occasions and working opposite in Syria, Iran, Yemen, Ukraine, the Baltic States, etc.