Putin is rehashing his nuclear threats — but this time, he may be threatening nuclear catastrophe in an effort to sway American voters

• Vladimir Putin made an explicit nuclear threat against the West this week.
• But experts remain skeptical of Putin's nuclear saber-rattling after three years of similar threats. 
• One expert suggested Putin is drumming up fear among American voters to cut US support for Ukraine. 

Russian President Vladimir Putin issued a new nuclear threat this week, threatening the West over its support for Ukraine in his most explicit intimidation tactic yet.