There are fires in Kiev, chaos in the Middle East and challenges at home and abroad, but is the biggest threat to our national security... something else?

Saying that climate change ranks among the world's most serious problems - such as disease outbreaks, poverty, terrorism and the proliferation of weapons of mass destruction - U.S. Secretary of State John Kerry called on all nations to respond to "the greatest challenge of our generation." FULL STORY

In the Crossfire, State Department Adviser Joe Cirincione and The Weekly Standard Editor Bill Kristol join Van Jones and Newt Gingrich to debate.

Gingrich has already been outspoken on the issue, calling for Kerry's resignation over Twitter.

We want you to weigh in: Secretary Kerry says climate change is 'perhaps the most fearsome weapon of mass destruction.' Do you agree?

Vote by tweeting Yes or No using #Crossfire or comment on our Facebook post. View results below or through our Poptip results page.