News Analysis: If passed, Iran nuclear deal will spur controversy in U.S.

Despite lack of clarity on exactly when and whether the U.S. and Iran will strike a deal over Tehran's nuclear program, one thing is certain - any deal U.S. President Barack Obama's administration brings home is bound to spark controversy in the U.S. Congress.

On Tuesday, negotiators decided to extend the deadline for a second time, and the talks are now looking at a July 10 deadline, as Iran now wants to add a few points to its list of demands. The two countries have been at odds over Iran's nuclear program for years, with Tehran claiming the program is peaceful and the U.S. saying the program is geared toward building nuclear weapons.

Whatever the two sides decide - considering a deal gets done - will not go over well with U.S. Congress, as not only Republicans but also some Democrats are ratcheting up pressure on the White House. Some Congressmen demand that Iran allow inspections of any and all of its nuclear facilities without prior notice, including at military sites.

"The Iran deal is going to be contentious on both sides of the political aisle because people (in the U.S.) are suspicious of Iran and there is a 35 year history of bad relations between the two countries," Brookings Institution's senior fellow Darrell West told Xinhua.

"It is going to take considerable persuasion to convince members (of Congress) to approve the deal and lift the trade embargo," he said of the sanctions that have wrecked Iran's economy and caused its currency to plummet.

"Many legislators want certainty that Iran won't get a nuclear weapon, and it is impossible even through a negotiated agreement to reduce that probability to zero," West said.

The hardest part for the Obama administration will be convincing Congress to lift the trade embargo, and there are no legal loopholes the White House can use to circumvent lawmakers.

"There is no way Obama can do that through an executive order. It will take the approval of the House and the Senate to get that bill through. The president will claim that he got the best deal possible, but there will be many who will claim that is not the case," West said.

A key disagreement between the U.S. and Iran is the level of access that inspectors will have to Tehran's nuclear program. Republican lawmakers want international inspectors to have full, unfettered access to all of Iran's nuclear facilities, including military sites.

If those terms are not met, Republicans could scuttle the deal by refusing to lift the sanctions, whether the White House likes it or not. If the U.S. Congress takes that road, Iran is highly unlikely to grant the West any access to its nuclear sites whatsoever.

Iran will say the U.S. broke the deal and will not open up its enrichment facilities, experts said, adding that Republicans may not approve any agreement that does not eliminate all enriched uranium and does not provide inspections of all nuclear sites.

Aside from inspection issues, Iran in the eleventh hour decided to add some points to its wish list, such as lifting sanctions on ballistic missiles and the termination of a United Nations arms embargo.

"Iran is just trying to get whatever it can, knowing that the U. S. would like to close the deal," David Pollock, senior fellow at the Washington Institute for Near East Policy, told Xinhua, adding that the main economic sanctions are Iran's top priority.

For Tehran, it is imperative to get rid of the sanctions that have wrecked its economy and caused its currency to plummet, but it remains unknown when and just how much sanctions will be lifted if a deal is cut.

Meanwhile, the negotiations have strained relations between the Obama administration and its main Middle East ally Israel, and some analysts said a nuclear deal with Iran is likely to make things worse between the White House and the government of Israel led by Prime Minister Benjamin Netanyahu.

Indeed, Netanyahu has been lambasting the agreement in the works as a bad deal, while not ruling out the option of launching preventive strike against Iran's nuclear facilities.

"Prime Minister Netanyahu has declared that a nuclear Iran would be an existential threat to Israel and has warned that Israel will not be bound by the agreement and may still consider a preventive strike against Iran's nuclear infrastructure, if the agreement does not adequately block Iran's path to a nuclear weapon, which seems to be the case," James Phillips, a Middle East expert at the Heritage Foundation, told Xinhua. Enditem