US Republicans laud Iran prisoner release, attack Barack Obama strategy

US Republican presidential candidates on Saturday praised the release of five Americans held in Iran, but said the Obama administration had conceded too much to win their freedom.

In a multi-pronged arrangement between two long-time enemies, the United States and Iran agreed on a prisoner swap on the same day their historic nuclear deal was fully implemented, which cleared the way for the lifting of sanctions on Tehran. On the presidential campaign trail, New Jersey Governor Chris Christie accused Obama of being "an expert at making bad deals with the Iranians."

Florida Senator Marco Rubio said the United States should not be involved in prisoner deals because they only encourage the taking of more hostages.

Jeb Bush, the former Republican governor of Florida, called for new sanctions against Iran and cited an exclusive report that the Obama administration refrained from imposing new sanctions in December 2015 after Tehran warned doing so could derail the prisoner deal. Bush praised the Americans' release but added: "The bigger issue is that we've legitimised a regime that shows no interest in actually moving forward with the so-called community of nations."

Separately, Democratic presidential candidate Hillary Clinton and Democratic Senator Richard Blumenthal on Saturday urged the administration to apply new sanctions in response to Iran's ballistic missile tests in violation of UN Security Council resolutions. "As president, my approach will be to distrust and verify" Iran's actions, Clinton said in a statement that also expressed her relief over the "safe return of American prisoners from Iran."

The new relationship unfolding between Washington and Tehran, after more than 30 years of bitter antagonism, could be Obama's signature foreign policy achievement, but it was also sure to remain a political flashpoint in the United States.

Republican front-runner Donald Trump said at a campaign event that Iran would realise a windfall of $150 billion from the lifting of economic sanctions under the nuclear pact, which is meant to keep Iran from developing a nuclear weapon. That figure has been widely disputed and is thought to be closer to $100 billion. Trump said he was happy Americans were being freed, "but I will tell you it's a disgrace that they were there for so long."

Democratic presidential candidate Bernie Sanders tweeted: "This good news shows that diplomacy can work even in this volatile region of the world."

Obama grants clemency 

In addition to the release of the five Americans, Obama has granted clemency to several Iranians convicted or facing trial in the United States over alleged Iran sanctions violations. At the same time, it was announced in Vienna that Iran was complying with the nuclear deal, which was a key step in the rolling back of the sanctions.

Congress could seek tougher oversight of the nuclear deal going forward. House of Representatives Speaker Paul Ryan, a top Republican lawmaker, criticized the lifting of the sanctions. "A bipartisan majority in the House voted to reject this deal in the first place, and we will continue to do everything possible to prevent a nuclear Iran," Ryan said in a statement.

Republicans have complained Obama's overtures to a country tagged by the U.S. State Department as a sponsor of "terrorism" were naïve, risking US national security and the existence of Israel, which some Iranian leaders have vowed to destroy.

Throughout 2015, the Obama administration, despite Republican opposition, worked feverishly to win an international deal that offered the end of crippling economic sanctions on Iran to entice it into dismantling its nuclear program.

Obama has long argued that a US policy to isolate Iran, in force since the 1979 takeover of the US embassy in Tehran and the hostage crisis there, did not slow Tehran's nuclear program. Early last May, Congress asserted its oversight role in any nuclear deal with Iran, approving legislation giving lawmakers the power to review and effectively block the deal.

But the combined opposition of Republicans, conservative lobbying groups and the Israeli government were not enough to sink the deal in Congress, as Obama's fellow Democrats mostly fell in line, blocking the disapproval measure in the Senate. As was the case with Obama's biggest domestic policy achievement so far - enactment of the "Obamacare" healthcare law in 2010 - not one Republican backed the president on the Iran deal.