Tehran's newfound willingness to allow an intrusive, international probe into the heart of its secretive and controversial nuclear program could defuse one of the world's most dangerous confrontations.
But the vague talk of a deal to be signed "quite soon," according to Yukiya Amano, head of the UN's nuclear watchdog agency must still evolve into a full-blown investigation before it can be considered the much-hoped-for breakthrough.
Still it might, eventually, confirm Tehran's much-disputed contention that it has no interest in joining the select club of nuclear-weapons states.
Tehran's willingness to accept international inspections didn't immediately placate Israel's hawkish Prime Minister Benjamin Netanyahu, who has threatened unilateral attacks on Iran's nuclear sites.
"Iran wants to destroy Israel and it is developing nuclear weapons to fulfill that goal," Mr. Netanyahu bluntly asserted, even as the UN nuclear chief was in Tehran for the talks that led to the qualified agreement on an inspection pact. "Against this malicious intention, leading world powers need to display determination and not weakness.
"They should not make any concessions to Iran," Mr. Netanyahu added.
But U.S. President Barack Obama has recently shown some flexibility and a degree of conciliation towards Iran's ruling mullahs – who still routinely refer to the United States as the Great Satan.
Even as top U.S. military and intelligence officials admit publicly that there is no 'smoking gun' evidence of a current or ongoing Iranian nuclear-weapons effort, the President has made clear to Tehran that it must come clean about its clandestine, scattered and sometimes deeply-buried nuclear facilities or face the risk of military action.
Inspections, followed by some sort of a broad pact on Iran's enrichment and other nuclear activities, could be a first step to lifting sanctions and – perhaps – a slow improvement in long-hostile relations between the Islamic Republic and the United States "We have offered Iran a clear path toward greater international integration if it lives up to its obligations, and that offer stands," Mr. Obama said earlier this spring. "But the Iranian government must now demonstrate through deeds its peaceful intentions or be held accountable to international standards and international law."
Mr. Amano's still-to-be-signed inspections deal may be the first indication that Tehran is serious about accepting intrusive international inspections.
On Wednesday, Iran is to meet the major powers (the so-called P5 plus one, consisting of the UN Security Council permanent members, Britain, France, China, Russia and the United States, along with Germany) in Baghdad for the next round in formal talks on bringing the entire Tehran's nuclear program inside the international nuclear regime.
After four years of thwarting International Atomic Energy Agency inspectors who wanted to probe evidence suggesting Tehran has, or perhaps had and has now suspended, a nuclear-weapons program, Mr. Amano's claim of a breakthrough could pave the way for further progress at the Baghdad talks.
And at last weekend's 'sleepover' summit at his Camp David mountain retreat, the President said: Iran's "continuing violation of international rules and norms and (its) inability thus far to convince the world community that it is not pursuing the weaponization of nuclear power is of grave concern to all of us."
One of the key tests of any inspections deal will be whether Tehran allows a probe of the Parchin, where IAEA officials suspect Iranian scientists conducted 'implosion' testing – the sort of nuclear triggering that would be essential for any weapons' program and pointless and unnecessary in a purely civilian, power-generations program.
Mr. Amano said Parchin was part of the proposed deal but offered no specifics.
In Iran, many – including those opposed to the Islamic government – regard international effort to probe and curb the nation's nuclear program as evidence of a double standard, noting that Israel's arsenal of nuclear weapons is mostly ignored by the major powers.
They also point to Supreme Leader Ayatollah Ali Khamenei's repeated assertions that Iran has no interest in acquiring nuclear weapons.
"From an ideological and juridical perspective, we consider developing nuclear weapons unlawful. We consider using such weapons as a big sin.
"We also believe that keeping such weapons is futile and dangerous, and we will never go after them," he said in February.
Verification, not just promises, is what the major powers, led by the United States, want from Tehran. Today's hint of a deal may be a first step.