At this writing, it is Friday night in Geneva, and there are press rumors that Iran and the P5+1 have overcome most but not all of the remaining major sticking points in negotiating a preliminary deal. According to latest reports, Secretary of State Kerry may be Geneva bound, which he wouldn’t be if the negotiations weren’t on the cusp. So let’s assume a preliminary deal is achieved: Iran will get some very minimal sanctions relief in return for essentially freezing its nuclear program for several months while a more substantive deal is negotiated. Presumably the parties will have found a way to split the difference, in some diplomatically ambiguous way, on Iran’s “right” to enrich uranium. In any case, any deal will acknowledge that Iran has the capacity to enrich uranium to non-weapons levels and will continue to do so, albeit under strict supervision and inspection. I believe such a deal would be in the interest of the United States and all oil consumers, because otherwise Iran is on track to develop a bomb fairly quickly if it wants, and no one really thinks that a war to stop that would solve the problem in any constructive way. It is in Israel’s interest too, an opinion Israeli military intelligence services have been leaking (contradicting the alarmist rhetoric of the Netanyahu government.)

Of course there is some question whether the newly elected Rouhani goverment will be allowed, by Iran’s hard liners, to cut such a deal which clearly puts Iran under oath to not develop nuclear weapons and subjects its facilities to all kinds of inspections. But there are no Iran experts to my knowledge who think that the new government doesn’t have the authority to really negotiate. A greater question is whether Congress will allow the Obama administration to negotiate such a deal. And that is where things get interesting.

Right now, there is every indication that Congress will try to mobilize to stop a deal. One close Congress watcher tallied up four Senate amendments already in the pipeline designed to limit Secretary Kerry’s negotiating flexibility, promise to support Israel’s effort to address “an existential Iranian nuclear threat,” support Israeli strikes against the “grave threat” posed by Syrian anti-aircraft missiles, and generally demand that Iran be “nuclear free.” More anti-diplomacy amendments are promised when the Senate returns from its Thanksgiving holiday.

The Senate’s hatred of Iran diplomacy is not really a mystery. Tom Friedman discussed it in a recent column, writing

[N]ever have I seen more lawmakers—Democrats and Republicans—more willing to take Israel’s side against their own president’s. I’m certain this comes less from any careful consideration of the facts and more from a growing tendency by many American lawmakers to do whatever the Israel lobby asks them to do in order to garner Jewish votes and campaign donations.

Shortly after the column appeared, two reporters got on an invitation-only conference call with Senator Mark Kirk, where the senator bragged to prospective donors how he coordinated legislative with AIPAC’s director Howard Kohr. Nevertheless, mention of the Israel lobby’s outsized influence remains single greatest taboo in American political life, and Friedman was instantly excoriated with accusations of anti-semitism from Elliott Abrams and Jennifer Rubin. But just as it gradually became permissible to claim the earth moved around the sun, the dangers to one’s professional life from talking about the Israel lobby’s influence are gradually but inexorably ebbing. Tom Friedman is pretty much immune, many times over: he is very supportive of a liberal Israel, has written a good book about the Middle East (and several others), he is tremendously wealthy, his stature in the world of opinion journalism exceeds that of Jennifer Rubin and Elliott Abrams many many times over.

Uri Avnery, the great Israeli activist and writer, explores the Netanyahu-Obama standoff here. He brings up Steve Walt and John Mearsheimer’s instant classic The Israel Lobby, whose main arguments are now being acted out on the national stage. (On a side note, Avnery states that The Israel Lobby argues that Capitol Hill is “Israeli-occupied territory”, much like Nablus and Ramallah. The book definitely does not claim that, and is on this and other questions far more nuanced. But I’m reminded of the person who did say it, as political talk show hyperbole, on The McLaughlin Group. It was of course Pat Buchanan, in 1990. He later told me that he had heard a Palestinian speaker use the line, thought it clever and filed it away, but believed it too hot to ever use himself. Then the subject came up on The McLaughlin Group and “It just came flying out.”)

So, on the one hand, you have a president and foreign affairs bureaucracy which wants to explore the possibility of a deal with Iran. On the other you have Israel’s government, which in the shrillest possible terms is shouting NO DEAL. Then you have the American people, who are divided on the matter but whose majorities are telling pollsters that on balance they favor such a deal, in some polls by 2-1 margins, in others somewhat less. And then you have a Congress pushing forward amendments designed to scuttle a deal and tie the president’s hands.

If a preliminary settlement is agreed upon in Geneva, the next six months will be a test of the Israel lobby’s power such as we have never seen. In the early 1980s, President Reagan barely prevailed in a months long face-off with Congress and Israel over whether the United States could sell AWACs, an airborne early warning system, to Saudi Arabia. “Reagan or Begin” was the catchword slogan. And Reagan of course had Boeing and other major arms manufacturers strongly on his side. But in fact, though Israel complained heatedly that this enhancement of Saudi defenses would reduce the “surprise attack” capacities of its air force, its effect on the overall Middle East has been slight.

The stakes of an Iran deal would not be slight. Iran will either be gradually reintegrated into the Middle East state system through diplomacy, or it will be left outside, its nuclear program advancing and belligerence enhanced. This is probably a recipe for war, quite possibly a major war, with consequences difficult to foresee. Put these ingredients together, and what can be foreseen is a political and moral battle in Washington that will make the AWAC’s struggle seem tiny by comparison.