Iranian President Hassan Rouhani speaks during a parliament session to defend his nominee for sports and youth minister in Tehran, Iran, Sunday, Nov. 10, 2013. Iran's conservative-dominated parliament rejected reformist ally of Rouhani for a ministerial post. In a vote on Sunday, 107 out of 253 lawmakers voted against Nasrollah Sajjadi who Rouhani nominated as the sports and youth minister. (AP Photo/Ebrahim Noroozi) Iranian President Hassan Rouhani  on Nov. 10. (Ebrahim Noroozi/Associated Press)

Three decades ago, a congressional test of wills over Middle East policy between an American president and an Israeli prime minister was dubbed “Reagan or Begin.” This week, the showdown on Iran negotiations might be described as “Barack or Bibi.”

Despite Obama administration opposition, Israeli Prime Minister Benjamin Netanyahu has been lobbying Congress to enact a new round of sanctions to squeeze Iran for additional concessions in the nuclear talks. “Iran is under economic pressure and continuation of this pressure, or increasing it, can lead to a much better result of a diplomatic solution in a peaceful manner,” Netanyahu said Sunday.

President Obama disagrees. He thinks that if Congress imposes additional sanctions now, it could torpedo the negotiations at a crucial stage. Iran’s supreme leader might conclude that hard-liners are seeking Iranian capitulation and regime change; in that case, U.S. officials suspect, the Iranians might decide their best option is to abandon the talks, press ahead with their nuclear program and ride out any Israeli or American attack that follows.

The 1981 “Reagan or Begin” battle involved congressional approval of airborne early warning and control (AWAC) radar-surveillance planes for Saudi Arabia. Saudi Arabia now is Israel’s de-facto ally against Iran, but back then it was a bitter foe. The Israeli government of Prime Minister Menachem Begin tried to block the sale despite President Reagan’s advocacy. Reagan won the test, and the AWAC sales went forward.

The Iran bargaining will resume this week in Geneva, as Iranian negotiators meet again on Wednesday and Thursday with representatives of the P5 + 1 coalition, which is made up of the five permanent members of the U.N. Security Council — United States, Russia, China, Britain and France — and Germany.

The trickiest issue probably will be Iran’s demand for some recognition of what it claims is its “right” to enrich uranium for civilian purposes, as some other signatories of the Non-Proliferation Treaty(NPT) have done. The United States insists that there’s no such right under the NPT. But negotiators have explored language that might provide Iran with a face-saving assurance that under a comprehensive deal to halt nuclear-weapons capability, it could have limited domestic enrichment for civilian use.

Diplomats often resolve such delicate issues through ambiguous language that each side can interpret as it chooses. Sometimes, they write side letters to the parties offering the desired assurances outside the formal text of an agreement. But in this case, U.S. officials appear convinced that language on enrichment must be clear and undiluted, with no winks or nods to convey subtle signals. The wording must be straightforward enough that both sides can go home and sell the agreement to their respective publics.

The issue has great symbolic importance to Israel, just as it does to Iran. Netanyahu fundamentally wants Iran to abandon any possibility of developing a nuclear weapon, which means dismantling its enrichment capability rather than codifying a supposed right to it.

U.S. negotiators believe that history shows the capitulation approach doesn’t work with Iran. Back in 2003, when President Hassan Rouhani was his country’s nuclear negotiator, Iran offered concessions to the West to limit its program. At that time, Iran had about 164 centrifuges. The United States and Israel refused that deal and decided to squeeze harder. Today, Iran has 19,000 centrifuges.

Now, U.S. officials fear a similar process will repeat itself, as Netanyahu’s push for the best possible deal sabotages the good deal that could freeze the Iranian program.

One interesting footnote is that a key player in the 1981 AWACs fight (and, indeed, the man who popularized the “Reagan or Begin” phrase) was Saudi Arabia’s Prince Bandar bin Sultan, then a diplomat in Washington and now Saudi intelligence chief.

Bandar’s erratic behavior in recent months has infuriated U.S. officials — and this anger is leading to some important new moves to consolidate U.S. policy with Gulf countries on Egypt and Syria (and in the process frustrate Bandar’s machinations).

On Egypt, the State Department is sending a team soon to the Gulf to work with Saudi Arabia and the United Arab Emirates on financial and political assistance to help Egypt’s transition to civilian democracy. On Syria, the United States is beginning to explore the possibility of creating a protected “safe zone” inside the country to aid humanitarian relief. That would be an important boost for the Syrian opposition and a check on the suffering of Syrian civilians during what could be a brutal winter.