Even before the official launch of the Bushehr nuclear reactor, Iranian officials have been lauding it as a victory for the Islamic republic against its enemies.
Senior MP Gholamreza Khalami said that the "arrogant powers" attempt to disrupt the project had failed.
Another MP described the opening of the plant as "a great victory for the Islamic Republic of Iran".
The hard-line Javan newspaper declared on Tuesday that the Russian decision to commission the plant "proves the victory of Iran's decisive demands against international pressure".
Amidst the defiance, you also sense relief that the first full-scale reactor in the Middle East is finally about to become operational.
In a ceremony on Saturday, officials from Iran and Russia, which has been building the reactor, will declare it operational.
It could be at least a month before it begins to generate electricity.
This weekend simply marks the moment when nuclear fuel will be brought inside the building, and the process begins of loading it into the reactor.
Nevertheless, this is the moment when Bushehr officially becomes a working nuclear reactor. It has taken a mere 35 years for the plant to be built.
When it was started in 1975, the Shah was still firmly in power; The Americans were keen for him to adopt nuclear technology; The German company Siemens sensed a promising business opportunity.
That all fell victim to politics, after the Islamic Revolution of 1979.
The Russian company AtomStroyExport took over the contract and resumed the work in 1995.
But the project continued to be repeatedly delayed.
Many Iranians feared it was what the Russians euphemistically call a "Dolgostroi" - a building project in which money is paid, and work continues, but no end is ever in sight.
Iranian officials openly expressed doubts about Russia's good faith.
They believed Moscow was succumbing to Western pressure to hold back on the project. Or perhaps, more prosaically, that the Russians were simply milking them for cash.
Now, despite a deterioration in Iranian-Russian relations, those suspicions can apparently be put to rest.
According to a White House official quoted in the Wall Street Journal, the latest development is the result of a deal between Washington in Moscow.
Washington agreed to lift its opposition to completing Bushehr, in return for Russia voting for the latest round of UN sanctions.
Certainly there has been a change of tune from Western officials recently.
Previously they had hinted that delay on the Bushehr project was one of the costs Iran was paying for lack of co-operation over its nuclear programme.
Now, Western officials are instead stressing that they have no objection to the demonstrably peaceful aspects of Iran's nuclear programme, such as Bushehr, only to other aspects of the programme which might have a military component.
Russia's involvement in the Bushehr project has been critical in allowing it to escape the net of international sanctions.
Not just is Russia building and operating the plant, it is also supplying the nuclear fuel and most importantly taking away the nuclear waste.
The main proliferation danger from reactors of this type is when countries extract the plutonium from the waste.
Russia's participation makes this unlikely, at least in the foreseeable future.
And Iran is not believed to possess a reprocessing plant that could extract plutonium, though experts say that one may be under development at a facility in Arak.
So most experts believe that in the near future, Bushehr does not present any immediate proliferation risk.
But others fear there is a possibility that some of the nuclear fuel could be diverted away from peaceful purposes, and eventually Iran could take over the plant from the Russians and begin reprocessing the waste.
Nevertheless for the moment the prospect of a military strike to prevent the nuclear plant becoming operational seems both unlikely and, according to the view of most Western experts, unnecessary.
After nuclear fuel is moved into the plant this weekend, such a strike would have the added danger of spreading nuclear material over a wide area.
The biggest international concern continues to centre on the Natanz centrifuge plant, which is being used to enrich uranium, a process with both peaceful and potentially military uses.