As part of the Reuters Summit on global climate and alternative energy, Reuters.com asked Carl Pope, executive director of the Sierra Club and Ian Hore-Lacy, director of public communication for the World Nuclear Association to discuss the role of nuclear energy. Here are their responses.

(Carl Pope’s rebuttal was posted at 8:30 a.m. ET on September 10.)

– Robert Gard (right), a retired U.S. Army lieutenant general and former president of both National Defense University and the Monterey Institute of International Studies, is chairman of the Washington, D.C.-based Center for Arms Control and Non-Proliferation, where Kingston Reif (left) is deputy director of nuclear non-proliferation. The views expressed are their own. –

Presidents Barack Obama and Dmitry Medvedev are meeting this week in Moscow for their first full summit. High on their agenda is the landmark 1991 Strategic Arms Reduction Treaty (START), which will expire on December 5. The expiration of START will mean the loss of the ability to legally limit and verify the two countries’ still enormous numbers of deployed nuclear weapons and delivery systems.

START greatly reduced the dangers posed by U.S. and Russian nuclear arsenals. Under the Treaty, the United States and Russia drastically reduced their deployed nuclear weapons. The agreement also contained a comprehensive set of verification and monitoring provisions that ensured that each side complied with its obligations.

Faced with the impending expiration of START, the Bush administration claimed that the United States and Russia no longer needed formal arms control agreements to manage their strategic relationship. Fortunately, Obama and Medvedev share a different view.

On April 1, Obama and Medvedev issued a joint statement in London in which they agreed to pursue “new and verifiable reductions in our strategic offensive arsenals in a step-by-step process.” During their summit this week, the two presidents could begin to solidify the actual framework of a START follow-on agreement.

The renewal of the U.S.-Russian arms control process is important for two reasons. First, deeper nuclear reductions can help to strengthen the nuclear Non-Proliferation Treaty (NPT), the first line of defense against the spread of nuclear weapons. Responsible U.S.-Russian nuclear reductions – a legal obligation under the NPT – is essential to non-nuclear weapons states’ willingness to continue to uphold their own NPT commitments not to pursue nuclear arsenals in the first place.

Second, as President Ronald Reagan repeatedly said, the United States must “trust but verify.”  START’s monitoring and verification provisions have brought predictability and stability to U.S.-Russian relations and prevented a renewed nuclear arms race. Without START’s verification tools, neither country would be able to know for sure that the other side was not attempting to achieve an advantage in nuclear forces.

There is broad and wide support, even among conservative Republicans, for reducing the size and role of nuclear weapons in U.S. national security policy. The recently released final report of the bipartisan Congressional Commission on the Strategic Posture of the United States concluded that “the moment appears ripe for a renewal of arms control with Russia, and this bodes well for a continued reduction in the nuclear arsenal.” The Commission included conservative Republican thinkers James Schlesinger, Keith Payne, and James Woolsey.

A second bipartisan report also urged the United States to negotiate mutual, verifiable, and legally binding nuclear reductions. The Council on Foreign Relations report stressed the importance of “efforts to renew legally binding arms control pacts with Russia by seeking follow-on agreements to START.” The report included such Republicans as Brent Scowcroft, Linton Brooks, and Frank Miller.

The appropriate mission for U.S. nuclear weapons is deterrence. Reducing the current U.S. nuclear stockpile will not undermine or endanger this mission. Present U.S. nuclear forces are more than sufficient to deter Russian and any other nuclear power’s forces, and further reductions will be undertaken in a bilateral, step-by-step process with Russia in close consultation with U.S. allies.

The United States and Russia have long-established treaties designed to control and limit nuclear weapons. Presidents Obama and Medvedev should use this week’s summit to build on those prior agreements, improve U.S.-Russian relations, and fashion a fundamentally safer world.

(Top photo: Russian Matryoshka dolls decorated with images of President Barack Obama, his Russian counterpart Dmitry Medvedev and Russia’s Prime Minister Vladimir Putin are seen on display at a market in Moscow July 3, 2009. REUTERS/Denis Sinyakov)

– Paul Taylor is a Reuters columnist. The opinions expressed are his own –

A wind of change is blowing through Iran, where hardline President Mahmoud Ahmadinejad faces an increasingly tough battle for re-election on Friday.

Whether or not Ahmadinejad fends off reformist Mirhossein Moussavi and two other candidates after a turbulent campaign, Iran is likely to be more open to talks with the United States on a possible “grand bargain” to end 30 years of hostility. Tehran will not give up its nuclear program, whoever wins. But it may be persuaded to stop short of testing or making a bomb.

There is a sense of deja vu about this election.

In 1997, a soft-spoken reformist, Mohammad Khatami, swept to a surprise landslide victory over the establishment candidate, Ali Akbar Nateq-Nouri, on a tide of young people and women clamoring for greater freedom. But after his supporters won control of parliament, the conservative clerical establishment used unelected institutions in Iran’s complex power system to neutralize Khatami and block his liberal agenda.

There is, however, a crucial difference this time.

The United States, which had a policy of “dual containment” of Iran and Iraq at the time, never seized the opportunity of Khatami’s victory to open a dialogue. Now, U.S. President Barack Obama is waiting with an outstretched hand and has made crucial gestures by accepting the Islamic Republic by its name, offering talks without pre-conditions and admitting Washington’s role in ousting nationalist Prime Minister Mohammad Mossadeq in 1953.

Obama’s respectful overtures in his Cairo speech calling for a new start with the Muslim world have played into the Iranian campaign.

Moussavi, a graying architect who was prime minister during the Iran-Iraq war in the 1980s, shortly after the 1979 Islamic Revolution, has become the unlikely standard bearer of a mass movement for change. Tehran is teeming nightly with green-clad young men and women demonstrating joyously against the fundamentalist Ahmadinejad. It will be hard to get the genie back into the bottle even if the incumbent wins.

The president is only number two in the hierarchy after Iran’s supreme leader, Ayatollah Ali Khamenei, who has the final say on all foreign policy and national security decisions, especially on the nuclear program, and controls the elite Revolutionary Guards.

The president is constrained by other powerful bodies such as the conservative judiciary, the Guardian Council, which can veto legislation and bar election candidates on Islamic grounds, and the Expediency Council, which arbitrates differences among the institutions and is headed by influential ex-President Akbar Hashemi Rafsanjani.

Policymaking involves endless bargaining among multiple stakeholders, but the supreme leader is the ultimate arbiter. For example, he is believed to have vetoed a proposal by Iran’s nuclear negotiator in 2006 to accept a temporary freeze on expanding uranium enrichment in order to launch negotiations with major powers represented by the EU’s Javier Solana.

While both main candidates say the nuclear program is irreversible, Ahmadinejad has ruled out further negotiations while Moussavi has advocated fresh talks.

Khamenei has endorsed Ahmadinejad’s re-election bid, but he is sensitive to public opinion and must be deeply worried by rifts that have opened in the establishment during the campaign.

The fissures were dramatized when Rafsanjani accused Ahmadinejad of lying and demanded that the leader call the president to order for airing corruption allegations against Rafsanjani during a televised debate. The ex-president warned Khamenei there could be an explosive situation after the election if he did not “extinguish the fire”.

This does not mean that Iran is on the brink of another revolution. The Islamic system is deeply rooted and the security forces have shown in the past they act swiftly and ruthlessly to crush any challenge.

Khamenei’s chief aim is to ensure the Islamic system’s survival. Public pressure for change and heightened factional tension should convince him, despite his deep suspicion of the United States, that it is worth exploring a deal with Obama.

Many experts believe that by completing the nuclear fuel cycle under international supervision, but without testing or building a weapon, Iran can deter its enemies and entrench its regional influence without incurring an Israeli or American strike. To spurn Obama’s offer and press ahead with an unsupervised nuclear program would invite such intervention and could put the regime’s survival at risk.

So whoever wins the vote, it could be “game on” in Tehran.

– Bernd Debusmann is a Reuters columnist. The opinions expressed are his own –

So what’s so difficult in getting Iran to drop its nuclear program? All it needs is a great American leader who uses sanctions to break the Iranian economy so badly that popular discontent sweeps away the leadership. It is replaced without a shot being fired.

That simplistic solution to one of the most complex problems of the Middle East was part of a keynote speech greeted with thunderous applause by 6,000 delegates to the annual policy conference of the American Israel Public Affairs Committee (AIPAC). The speaker: Newt Gingrich, a former speaker of the U.S. House of Representatives and a likely Republican presidential candidate in 2012.

In the fourth month of the administration of President Barack Obama, who favors talking to America’s adversaries rather than ousting them, the Gingrich prescription sounded like a throwback to the days when neo-conservatives predicted that the U.S. troops invading Iraq would be pelted with flowers and sweets. Wishful thinking at its finest.

But in panel discussions and forums at AIPAC, one of the most powerful lobby groups in the United States, the idea of sharply tightened sanctions had plenty of proponents. The preferred lever: cutting off gasoline supplies to Iran, which relies on imports for around 40% of its domestic consumption.

On the final day of the conference this week, several thousand AIPAC activists converged on Congress to press their representatives for passage of pending legislation to sanction companies that sell, ship, finance or insure gasoline exports to Iran. Firms that continued dealing with Iran would be banned from doing business with the U.S.

Would an additional layer to a stack of sanctions imposed since 1995 get the Iranians to drop what the West insists is work toward a nuclear bomb? There is no reason to believe it would. There is every reason to believe more sanctions would inflict hardship on the Iranian people.

“With all the economic pain sanctions have imposed on the Iranian economy, there has not been a single instance in which that pain has translated into a desirable change in the Iranian government’s policies,” Trita Parsi, the president of the Washington-based National Iranian American Council, told a congressional hearing last month. “The Iranian people have suffered the brunt of the economic pressures.”

A MATTER OF NATIONAL PRIDE

That tends to be the case with most sanctions that seek to change a government’s behavior or its ouster. A case in point closer to Washington than Tehran — Cuba. Almost five decades of U.S. economic sanctions have failed to bring down Fidel Castro or the brother who succeeded him.

Iran introduced gasoline rationing in June, 2007, a move that sparked riots in Tehran, with angry citizens setting ablaze gasoline stations. It was one of the most visible demonstrations of anger against the Iranian government since President Mahmoud Ahmedinejad took office in 2005.

But by and large, say Trita and other Iran experts, a good deal of the people’s anger over economic duress is directed against the United States, more so because the nuclear program has become a matter of national pride. It enjoys such broad public support that no politician running for office would risk advocating its termination.

So it would be naïve to expect public Iranian concessions on the nuclear front before the June 12 presidential elections. Registration for candidates opened this week and Ahmedinejad is expected to run for another four-year term. His most serious challenger to have announced his candidacy so far is a moderate, Mirhossein Mousavi, who was prime minister during the Iran-Iraq war from 1980 to 1988.

When he campaigned for the presidency and announced he was prepared to open a dialogue with Iran, Barack Obama said he would do so without “self-defeating preconditions.” But he also spoke in favor of sanctions, including the idea of throttling gasoline supplies. Overall strategy is still a work in progress.

As far as “self-defeating preconditions” go, setting an August deadline for Iran to curb its nuclear program, as did Israeli Foreign Minister Avigdor Lieberman this week, must surely rank at the top of the list. It’s an either-or proposition which makes a mockery of the word diplomacy.

It remains to be seen whether Israeli Prime Minister Benjamin Netanyahu insists on that timeline when he meets Obama in Washington on May 18. So far, they don’t seem to be of one mind on Iran, an absolute priority for Netanyahu, part of intertwined Middle East problems (including the Israeli-Palestinian conflict) for Obama and his team.

Robert Satloff, head of the Washington Institute for Near East Policy, a pro-Israeli think tank, put it in stark terms at an AIPAC panel discussion when speakers were asked to predict the state of U.S.-Israeli relations in a year’s time: “I fear that if we and the Israelis are not totally on the same page from A to Z on this issue…next year we may be dealing with the most serious face-to-face disagreement in the 61 years of this relationship.”

Next year, if not before.