What Are The Greatest Threats To The US?

What Do Americans Perceive as the Greatest Threats to the U.S.?

ISIS 

Al-Qaeda

North Korea

Russia (Video via President of Russia)

Nuclear weapons (Video via Khamenei.ir)

But which is the greatest actual threat? (Video via U.S. Army)

"My assessment today, Senator, is that Russia provides the greatest threat to our national security," said Marine Gen. Joseph Dunford.

"But the biggest threat of all is the nuclear ambitions of the radical Islamists who control Iran," said Sen. Lindsey Graham.

"Now you say ISIL, some of us say ISIS, some say Islamic State. It's all the same thing. Is that now a bigger threat to the U.S. homeland than Al-Qaeda?" Wolf Blitzer asked. 

"Yes. ... ISIL is not your parent's Al-Qaeda," FBI Director James Comey replied.

"A nuclear Iran poses the greatest national security threat to this country," said Sen. Ted Cruz.

"Cyber poses a very complex set of threats," said former U.S. Air Force Lt. Gen. James Clapper.

"Ebola is obviously a very severe security threat for our entire nation," said presidential candidate Ben Carson.

"So I'm here today to say that climate change constitutes a serious threat to global security, an immediate risk to our national security," said President Obama.

The 2015 U.S. National Military Strategy says Russia, Iran, North Korea, China and international terrorism are currently the greatest security threats to the U.S. (Video via U.S. Department of Defense / Spc. Tianna Field)

This video includes music from Yinyues / CC BY 3.0.