North Korea is ramping up its nuclear capabilities.
India and Pakistan are still growing their arsenals - and facing off against each other.
The Iranian agreement is either one of the best deals to curb nuclear weapons, or gives Iran a free pass to make them.
A presidential candidate has suggested giving Japan and South Korea nuclear weapons. And, he would bomb Europe if the circumstances were right.
On Wednesday, Las Vegas will be the site of an unprecedented discussion featuring three internationally recognized experts on the expanding global nuclear threat.
The panel discussion, “21st Century Global Nuclear Challenges" is sponsored by the National Atomic Testing Museum and UNLV.
One of the speakers is Dr. Siegfried Hecker, former director of Los Alamos National Laboratories and now research professor at Stanford.
Dr. Hecker was the last American to visit North Korea’s nuclear facilities - he was there seven times - and he just returned from Russia. He’s also familiar with Nevada and Las Vegas, as he led Los Alamos during the lab's peak production of underground nuclear weapons experiments in Nevada.
Dr. Hecker is generally optimistic about the way the arsenal for the former Soviet Union has been dealt with, but he's very worried about terrorists groups getting fissile material, which is the material capable of sustaining a nuclear fission chain reaction, even if they don't have traditional warheads.
But he said he and his counterparts in Russia have worked since the collapse of the Soviet Union to keep the material out of the hands of terrorists and so far they've been able to do it.
The relations between the Russian government and American government over the past several years have not helped their efforts but they do continue to work together.
As for North Korea, Dr. Hecker said when he was last there in 2010 they showed him the facility they could use to make enriched uranium, which is a step in the nuclear weapon making process.
He said by now the best guess is that North Korea has 15 or so nuclear devices, but they don't have the missiles to carry the devices to the United States.
“They have an arsenal we need to be concerned about,” he said.
Hecker doesn't believe North Korea will use the devices to bomb another country and are using it for defense. However, he is worried about how having the devices will change North Korea's view of the world.
"I’m concerned that it makes the regime much more aggressive believing that they have a nuclear arsenal," he said.
Dr. Siegfried Hecker, Senior Fellow at the Freeman Spogli Institute for International Studies, Research Professor of Management Science and Engineering