A group of nuclear weapons specialists has issued ominous warnings before members of the U.S. Congress that terrorist groups like al-Qaida could launch a massive attack on the United States and currently there is little to deter or defend against such a strike.  VOA correspondent Meredith Buel has details from Capitol Hill.

Sidney Drell, an arms control specialist and physicist at Stanford University, told members of the Senate Armed Services Committee the United States has entered, what he calls, a "dangerous time." 

"I view us on the precipice of entering a new and more dangerous nuclear era with the spread of technology, which means, in particular, the enrichment of uranium, which makes it possible for more societies to enter the nuclear club," he said.  "That raises the danger of nuclear weapons getting in the hands of terrorist groups and others unrestrained by the norms of civilized behavior as we know it and therefore these weapons become more likely to be used."

The dean of Georgetown University's school of Foreign Service, Robert Gallucci, agrees.

Gallucci, a former U.S. Assistant Secretary of State for Political-Military Affairs, says the most dangerous threat is that a terrorist group will smuggle a nuclear weapon into the United States.

"The most likely is that a terrorist group, al-Qaida or an al-Qaida cousin would acquire a nuclear weapon and introduce it into the United States," he explained.  "It seems to me that that is a threat against which we have neither a defense nor a deterrent."

Gallucci says a maximum effort needs to be made to prevent terrorists from acquiring or manufacturing a nuclear weapon.

He says this should be done by convincing countries with nuclear materials to secure them. 

"If we discover that a country has purposely transferred fissile material or a nuclear weapon to a terrorist group, we ought to be telling them in advance that we will treat them as though they were the one who launched the attack and they should expect devastating retaliation," he added.

Gallucci says he is especially concerned about unauthorized transfer of nuclear materials from Russia and Pakistan and the intentional transfer from North Korea and eventually Iran.