SUMMARY: We look at an ad that touts Obama's nuclear record and a chain e-mail that slams it.

Nuclear weapons are the topic for a recent campaign ad promoting Sen. Barack Obama and an anonymous e-mail attacking him.

In a new television ad, Obama says the United States needs to take the lead internationally to keep nuclear weapons out of the wrong hands.

"The single most important national security threat that we face is nuclear weapons falling into the hands of terrorists," Obama says in the ad. "What I did was reach out to Sen. Dick Lugar, a Republican, to help lock down loose nuclear weapons. We have to lead the entire world to reduce that threat. We can restore America’s leadership in the world."

We looked into the legislation Obama teamed up with Lugar to pass and rule his statement True.

We also looked at a chain e-mail that claims Obama wants to "unilaterally disarm" the United States. Obama never said that; he said he wanted a world free of nuclear weapons, as have foreign policy experts on both sides of the partisan divide. For nonexistent evidence, we rule this claim False.