By Jim Garamone American Forces Press Service WASHINGTON -- Proliferation of weapons of mass destruction, including the means to launch them, constitute the greatest single threat to vital U.S. national interests, the directors of the CIA and the Defense Intelligence Agency said Feb. 9. CIA Director George Tenet told the Senate Armed Services Committee the "emblematic" issue today is the proliferation of weapons of mass destruction. In 1998, India and Pakistan both exploded nuclear devices. The United States has continuing concern over Iraq's weapons of mass destruction program, and intelligence officials are worried about Russian weapons of mass destruction security, Tenet said. DIA Director Army Lt. Gen. Patrick Hughes said the international security environment remains "volatile, complex and very difficult." He said he expects global turmoil to continue through the next decade and possibly worsen because its underlying causes -- political, economic, social, technological and demographic issues -- will remain in place. Tenet said the U.S. intelligence agencies are looking at these and many other threats, but "there is a continued and growing risk of surprise." The United States is concerned about continuing weapon proliferation problems in the former Soviet Union. While Russia has new controls on missile technology exports, it hasn't followed through on enforcing them, Tenet said, noting Russia has been exporting technology to Iran. "This assistance is continuing as we speak," he said. "And there is no doubt that [this assistance] will play a crucial role in Iran's ability to develop more sophisticated and longer-range missiles." Russia's continuing societal and economic woes threaten to worsen making the situation more threatening, he said. Hughes said he, too, was concerned that countries like Iran and North Korea will develop weapons of mass destruction and the means to launch them. He said the threat would first be felt regionally. "This more diverse and complex strategic nuclear threat affects post-Cold War thinking about nuclear deterrence, strike-and-response policy, force posture and strategic targeting," he said. Tenet said China's situation "is a mixed picture." It has tightened exports of sensitive technology, but neither he nor Hughes could assure Congress those controls have been effective. "In short, … our guard remains up on this question," Tenet said. As North Korea's economy deteriorates, the impetus increases for it to sell its know-how in weapons of mass destruction. "North Korea's sales of such products over the years have dramatically heightened the [weapons of mass destruction] threat in countries of key concern, such as Iran and Pakistan," Tenet said. The North Koreans have been instrumental in helping Iran and Pakistan leap-frog technologies to develop their own missiles. Through North Korea's help, he said, India, Iran and Pakistan also have become technology exporters. Tenet said the United States is concerned North Korea may be developing a covert program to produce plutonium -- a key ingredient in nuclear weapons. "The key target for us to watch is the underground construction project at Kumchangni, which is large enough to house a plutonium production facility and perhaps a reprocessing plant as well," Tenet said. "The [North Korean] missile story is no more encouraging." North Korea's launch of the Taepo Dong I in August showed it could deliver a very small payload over intercontinental ranges, Tenet said. He said they're working on the Taepo Dong II, a two- stage design believed to have the range to reach the United States.