Nations of the world &#8212; particularly the United States &#8212; must firmly renounce atomic weapons to avert an irreversible humanitarian crisis, the first foreign-born chairman of Hiroshima's atomic-bomb memorial said Thursday.</PARAGRAPH> <PHOTO> <TABLE WIDTH='250' ALIGN='RIGHT' BORDER='0'> <TR> <TD><IMG ALT='News photo' BORDER='0' SRC='../images/photos2007/nn20070921a6a.jpg' WIDTH='250' HEIGHT='250'/></TD> </TR> <TR> <TD><FONT SIZE='1'><B>Steven L. Leeper, head of the Hiroshima Peace Culture Foundation, speaks at a news conference Thursday in Tokyo. </B> ERIC PRIDEAUX PHOTO</FONT></TD> </TR> <TABLE> </PHOTO> <PARAGRAPH>Antiwar activist and longtime Hiroshima resident Steven L. Leeper, appointed head of the Hiroshima Peace Culture Foundation in April, said he hoped a poster campaign the organization has launched in the United States to commemorate Japan's atomic bombings will encourage Americans to speak out about never using the weapons again under any circumstances, even as prominent U.S. politicians refuse to completely reject the option.</PARAGRAPH> <PARAGRAPH>The exhibit of some 30 posters tells the story of the August 1945 atomic bombings of Hiroshima and Nagasaki. It is planned to be held at 101 sites across the U.S. &#8212; two in every state and one in Washington D.C. Survivors are to speak at as many venues as possible.</PARAGRAPH> <PARAGRAPH>The exhibit started on Sept. 14 in Rochester, N.Y., and will continue through 2008, said Leeper, adding that public interest has been strong. Leeper said that among those candidates with any reasonable chance of winning the 2008 U.S. presidential election, all but Barak Obama, 46, the Democratic senator from Illinois, have been reluctant to take atomic weapons completely off the table. Thus, rather than sway politicians, the campaign's goal is to create a groundswell of opposition at the grassroots level, he said. </PARAGRAPH> <PARAGRAPH>'We want to remind –

that nuclear weapons are extremely dangerous and should never be used," said Leeper, a 59-year-old Illinois native, at the Japan National Press Club in Tokyo. "We want them to make sure that they communicate that to their leaders."

Leeper is particularly alarmed by the U.S. for its flirtation with mini-nukes and its decision last year to give India civilian nuclear knowhow and access to nuclear fuel even though it is not a signatory to the Nuclear Nonproliferation Treaty. Instability in other regions could also spark chaos, said Leeper.

"Right now we face the serious possibility that the United States could use a nuclear weapon in Iran," he said.