Conservative US leaders, fond of finger-pointing at France in recent years, lavished praise on Paris Sunday for blocking an agreement between Western powers and Iran over Tehran's nuclear program.

"Vive la France!" tweeted Senator John McCain, an outspoken voice on national security issues.

"France had the courage to prevent a bad nuclear agreement with Iran," he said, after the weekend announcement that no agreement had been reached between the United States, China, Russia, Britain, France and Germany, known as the P5+1.

During three days of intense negotiations in Geneva, France repeatedly voiced concerns over various points in a possible deal and its lack of guarantees, a position that had Iran calling it a negotiations spoiled sport.

"Thank God for France and thank God for push back," said hawkish Senator Lindsey Graham on CNN's "State of the Union" show.

"The French are becoming very good leaders in the Mideast," Graham said, also suggesting he would be in favor of more sanctions against Iran.

"My fear is that we're going to wind up creating a North Korea-type situation in the Mideast, where we negotiate with Iran and one day you wake up... and you're going to have a nuclear Iran," he said.

According to Hussein Ibish, a senior fellow at the American Task Force on Palestine, France "has become the most hawkish Western nation on matters involving the Middle East and neighboring areas."

"France pushed the Libyan intervention, invaded and rescued Mali" and "was most enthusiastic about strikes against Syrian chemical weapons targets," he said.

This August, France made clear its wish to take military action alongside the US against the Syrian regime, making Paris Washington's main ally in the crisis after Britain backed out of any strikes.

It was a stark turnabout from just a decade ago when then French president Jacques Chirac's opposition to the Anglo-US offensive against Saddam Hussein's regime in Iraq soured Franco-US ties.

So deep was the animosity -- led by conservatives for the most part -- that French fries were renamed "freedom fries" in some American restaurants, as well as in cafeterias of the US House of Representatives.

At the time, anti-French hate messages also were brandished in public, including on T-shirts and billboards.

Despite the blockage being music to some Republicans' ears, the motivations of France, a historical US ally for more than 200 years, were likely self-serving, according to some analysts.

"It is striking a lot of people as being surprising and the question is what is motivating France to take this position at this point?" said Alireza Nader, senior international policy analyst with the RAND Corporation.

"Even countries like France are very much aware of the balance of power in the Middle East and they want to protect their interests."