Today, Russia has an active nuclear arsenal of about 4,500 nuclear warheads. About 1,600 of these warheads are deployed on land-based intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and at heavy bomber bases.
Implications for European security and nuclear arms control
www.swp-berlin.org
American response will be "conventional."
Putin is not insane either:
The Russian leader insists his country would only use its nuclear arsenal in response to a strike.
www.bbc.com
Chill, dude.