Israeli officials need to admit that the country has nuclear weapon capabilities and eliminate the censorship they have imposed on the country for half a century, an expert on the subject said Wednesday.

Avner Cohen, senior research fellow at the National Security Archive in Washington, D.C., and at the Center for International and Security Studies at the University of Maryland, spoke on "Nuclear Weapons and Democracy: The Israeli Case" to a packed room at Lehigh University.

His talk focused on Israel rising to become a nuclear power, and he did not mention the fighting going on between Israelis and Palestinians over a corner of the Gaza Strip. The fighting, which started in September, has included mortar attacks and bombings.

In his 1998 book "Israel and the Bomb," Cohen broke the code of silence surrounding Israel's nuclear weapons capacity. Since the establishment of the state in 1948, Israeli officials have refused to acknowledge that the country had nuclear weapons. Cohen's book provided the first detailed historical account of Israel's development of nuclear power.

"When Israel first developed nuclear weapons, it was in their best interest to keep it quiet," Cohen said. "But now, it is time they take responsibility and open this black box."

Cohen has written on issues related to nuclear proliferation in the Middle East and nuclear deterrence and morality for more than 10 years. In 1987-88, he was a research fellow at Harvard University's Kennedy School of Government, where he developed the notion of "opaque" nuclear proliferation, which is when everyone knows a country has the weapons, but the country never admits it.

Cohen feels that by never publicly admitting the country has nuclear weapons and censoring anyone from talking about it, Israeli officials are hurting the country's democracy.

"When they first started the program to create these weapons, they were a young nation and secrecy was the wise decision," he said. "But now that Israel is over 50 years old, they can handle coming forward and admitting it.

"In all nations that developed nuclear weapons, secrecy was a part of the project that ended with the successful completion of the project -- everywhere except Israel."

And because officials have never admitted to having these weapons, there is no way for the government, and people, to keep a check on the powers that control them.

"Not only do they have to admit they have them, they have to create an agency that will regulate them," Cohen said.

His talk was sponsored by the Philip and Muriel Berman Center for Jewish Studies, Lehigh's international relations department and the Science, Technology and Society Program.