Is lull in US-Iran tensions just calm before the storm? Talks will tell.

A better-than-expected first round of talks on Iran's nuclear program is the key reason for the lull. But some experts say any optimism may be just wishful thinking, and a lot can go wrong with Round 2.

Strong assumptions in March that airstrikes on Iran’s nuclear installations were in the cards for as early as this spring have given way to a sense that military intervention, either by Israel or the United States, is increasingly unlikely any time this year.

But this could just be the calm before the storm, according to some nuclear experts, who point out that everything may still ride on the outcome of international talks with Iran set for later this month.

The current lull in bellicose rumblings is largely the result of the initial meeting of international powers and Iran in Istanbul last month, which was judged by virtually all sides involved as having gone better than anyone anticipated.

European and Obama administration officials say Iran arrived at those talks ready to discuss its nuclear program – which was not the case when the same powers met with Iran the last time, in January 2011. At the same time, Iranian officials, including some influential clerics, have emphasized that the talks offer the chance of reaching a satisfactory resolution for all sides.

There are a number of key factors that explain why the Istanbul talks between Iran and the five permanent members of the United Nations Security Council – the US, China, Russia, Britain, France – plus Germany went off better than many expected and calmed March’s war drums, experts say:

• Toughened international sanctions are getting Iran’s attention, with the very real prospect of an embargo on Iran’s oil exports going into effect this summer taking an even bigger bite out of Iran’s economy

• Western powers stopped publicly demanding that Iran give up all uranium enrichment, with US officials suggesting that a deal might be worked out in which Iran retained enrichment capabilities, under strict international monitoring, for civilian power generation

• Israel’s hints at imminent airstrikes on Iran’s nuclear facilities focused minds on both sides of the talks.

On that last point, some experts note that it was around the time of Israeli Prime Minister Benjamin Netanyahu’s visit to Washington in March that President Obama publicly ruled out a policy of “containment” toward Iran, under which the US would accept a nuclear Iran but develop a regional policy to limit Iran’s influence and the spread of nuclear weapons around the Middle East.

Obama continues to insist that a nuclear Iran is not acceptable and that “all options” for preventing that “remain on the table.”

But Mr. Netanyahu’s tough talk, including in Washington, also spawned a debate in Israel that left hawkish civilian leaders pitted against military and intelligence officials, both serving and retired, who sounded much less enthusiastic about the prospects for an Israeli military intervention in Iran.

Yet all of these factors could turn out to be temporary, with the result that the current quietude over Iran proves to be short-lived, experts add – especially if the May 23 talks in Baghdad collapse and indeed prove to have been the “last chance” for diplomacy that Secretary of State Hillary Rodham Clinton described them as last month.

Some analysts suspect the Baghdad talks may simply reveal that the optimism coming out of the initial Istanbul meeting was largely wishful thinking. “My sense is that not a lot was accomplished there [in Istanbul],” says Jamie Fly, executive director of the Foreign Policy Initiative and a former Iran specialist on the National Security Council under President George W. Bush. What the talks are providing, he adds, is the time for Iran to “get close to being a de facto nuclear state, if it’s not already there.”

Among the wrenches that could be thrown in the diplomatic works:

• An inability to reach an accord on what to do with Iran’s stockpile of 20-percent enriched uranium, which puts Iran much closer to the 90-percent enriched uranium needed to fuel a nuclear weapon.

• A demand from Iran that economic sanctions be lifted before it agrees to limit its nuclear program.

Even if Iran accepts giving up its stockpile of 20-percent enriched uranium – through something like the fuel-swap deal the parties almost agreed on in 2009 – the capacity and dispersed nature of Iran’s program will mean that any level of enrichment will remain a problem, some experts say.

“Once you’ve legitimized their program, they’re allowed [under current international atomic energy regulations] to expand it,” says Greg Jones, a senior researcher at the Nonproliferation Policy Education Center in Arlington, Va. While he agrees with those who don’t believe Iran has made the decision to produce nuclear weapons, he says acquiescing to Iran enriching to the level required for civilian nuclear power would allow it to get to a point where it could “race forward” to the bomb in a matter of weeks.

“They could easily justify expanding the 3.5 percent [enrichment],” Mr. Jones says, “and from there they could get to HEU [the highly enriched uranium required for a weapon] in a matter of weeks.”

That argument explains why Netanyahu expressed alarm over suggestions that international powers were softening an earlier demand that Iran stop all enrichment.

Jones says another reason the prevailing hope in a diplomatic solution will prove to be short-lived is that the economic sanctions won’t be tight enough to force Tehran’s hand. “I’m not sure the sanctions ultimately have enough universality to have the bite necessary” to compel Iran to back down, he says, noting that countries like India and China continue to purchase Iranian oil.

Proceeding from the perspective that the “lull” in consideration of a military option will almost certainly come to an end, Mr. Fly says sooner or later an inability to reach a satisfactory accord will lead to the conclusion that the problem that must be dealt with is the government in Tehran.

“Changing the regime in the long run is the only solution to this,” he says.

That is not the policy of the current administration in Washington (some of this year’s Republican presidential candidates, including Newt Gingrich, were vocal advocates of that idea), but Fly says the US should at least establish – and stick to – a list of “red lines” that Iran would not be allowed to cross without swift consequences.